Pharmaceutical compositions and methods for relieving pain and treating central nervous system disorders

ABSTRACT

Patients susceptible to or suffering from disorders, such as central nervous system disorders, which are characterized by an alteration in normal neurotransmitter release, such as dopamine release (e.g., Parkinsonism, Parkinson&#39;s Disease, Tourette&#39;s Syndrome, attention deficient disorder, or schizophrenia), are treated by administering a compound of Formulas 1 or 2, as described herein. The compounds of Formulas 1 and 2 are also useful for treating pain, and treating drug addiction, nicotine addiction, and/or obesity. The compounds can exist as individual stereoisomers, racemic mixtures, diastereomers and the like.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.12/123,530, filed May 20, 2008, which is a divisional of U.S.application Ser. No. 10/711,969, filed Oct. 15, 2004, now U.S. Pat. No.7,402,592, which claims priority to Provisional Application Ser. No.60/511,697, filed Oct. 15, 2003, each of which is herein incorporated byreference.

FIELD OF THE INVENTION

The present invention relates to pharmaceutical compositions,particularly pharmaceutical compositions incorporating compounds thatare capable of affecting nicotinic acetylcholinergic receptors (nAChRs).The present invention also relates to methods for treating a widevariety of conditions and disorders, particularly conditions anddisorders associated with dysfunction of the central and autonomicnervous systems, and the treatment of addiction, including smokingaddiction and addiction to narcotics and other drugs, and obesity.

BACKGROUND OF THE INVENTION

Nicotine has been proposed to have a number of pharmacological effects.See, for example, Pullan et al., N. Engl. J. Med. 330:811 (1994).Certain of those effects may be related to effects upon neurotransmitterrelease. See for example, Sjak-shie et al., Brain Res. 624:295 (1993),where neuroprotective effects of nicotine are proposed. Release ofacetylcholine and dopamine by neurons upon administration of nicotinehas been reported by Rowell et al., J. Neurochem. 43:1593 (1984); Rapieret al., J. Neurochem. 50:1123 (1988); Sandor et al., Brain Res. 567:313(1991) and Vizi, Br. J. Pharmacol. 47:765 (1973). Release ofnorepinephrine by neurons upon administration of nicotine has beenreported by Hall et al., Biochem. Pharmacol. 21:1829 (1972). Release ofserotonin by neurons upon administration of nicotine has been reportedby Hery et al., Arch. Int. Pharmacodyn. Ther. 296:91 (1977). Release ofglutamate by neurons upon administration of nicotine has been reportedby Toth et al., Neurochem. Res. 17:265 (1992). Confirmatory reports andadditional recent studies have included the modulation, in the centralnervous system (CNS), of glutamate, nitric oxide, GABA, takykinins,cytokines and peptides (reviewed in Brioni et al., Adv. Pharmacol.37:153 (1997)). In addition, nicotine reportedly potentiates thepharmacological behavior of certain pharmaceutical compositions used forthe treatment of certain CNS disorders. See Sanberg et al., Pharmacol.Biochem. & Behavior 46:303 (1993); Harsing et al., J. Neurochem. 59:48(1993) and Hughes, Proceedings from Intl. Symp. Nic. S40 (1994).Furthermore, various other beneficial pharmacological effects ofnicotine have been proposed. See, for example, Decina et al., Biol.Psychiatry 28:502 (1990); Wagner et al., Pharmacopsychiatry 21:301(1988); Pomerleau et al., Addictive Behaviors 9:265 (1984); Onaivi etal., Life Sci. 54(3):193 (1994); Tripathi et al., J. Pharmacol. Exp.Ther. 221:91 (1982) and Hamon, Trends in Pharmacol. Res. 15:36.

Various nicotinic compounds have been reported as being useful fortreating a wide variety of conditions and disorders. See, for example,Williams et al., Drug News & Perspectives 7(4):205 (1994); Arneric etal., CNS Drug Rev. 1(1):1 (1995); Arneric et al., Exp. Opin. Invest.Drugs 5(1):79 (1996); Bencherif et al., J. Pharmacol. Exp. Ther.279:1413 (1996); Lippiello et al., J. Pharmacol. Exp. Ther. 279:1422(1996); Damaj et al., J. Pharmacol. Exp. Ther. 291:390 (1999); Chiari etal., Anesthesiology 91:1447 (1999); Lavand'homme and Eisenbach,Anesthesiology 91:1455 (1999); Holladay et al., J. Med. Chem. 40(28):4169 (1997); Bannon et al., Science 279: 77 (1998); PCT WO 94/08992, PCTWO 96/31475, and U.S. Pat. Nos. 5,583,140 to Bencherif et al., 5,597,919to Dull et al., 5,604,231 to Smith et al. and 5,852,041 to Cosford etal. Nicotinic compounds are particularly useful for treating a widevariety of CNS disorders. Indeed, a wide variety of nicotinic compoundshave been reported to have therapeutic properties. See, for example,Bencherif and Schmitt, Current Drug Targets: CNS and NeurologicalDisorders 1(4): 349 (2002); Levin and Rezvani, Current Drug Targets: CNSand Neurological Disorders 1(4): 423 (2002); O'Neill et al., CurrentDrug Targets: CNS and Neurological Disorders 1(4): 399 (2002); U.S. Pat.Nos. 5,1871,166 to Kikuchi et al., 5,672,601 to Cignarella, PCT WO99/21834 and PCT WO 97/40049, UK Patent Application GB 2295387 andEuropean Patent Application 297,858.

Pain can be classified in various ways and can be characterized by avariety of geneses and etiologies (e.g., inflammatory pain, neuropathicpain, chronic pain). Current pain therapy is dominated by two classes ofdrugs, the non-steroidal anti-inflammatory drugs (NSAIDs) and theopioids, both of which have significant therapeutic liabilities. Variouscompounds which target nAChRs have been shown to be effective intreating one or more kinds of pain in animal models. See for instance,Damaj et al., J. Pharmacol. Exp. Ther. 291:390 (1999); Damaj et al.,Neuropharmacology 39:2785-2791 (2000); Chiari et al., Anesthesiology91:1447 (1999); Lavand'homme and Eisenbach, Anesthesiology 91:1455(1999); Holladay et al., J. Med. Chem. 40(28): 4169 (1997); Bannon etal., Science 279: 77 (1998); and Bannon et al., J Pharmacol Exp Ther.285:787-794 (1998). Depending on the etiology of the pain, both the α4β2and the α7 nAChR subtypes (which are CNS nAChR subtypes) have beenidentified as targets for analgesia. It would be beneficial to provide,with a single pharmaceutical agent, relief from multiple kinds of pain.It would also be beneficial to provide such relief without thegastrointestinal liabilities of the NSAIDs or the abuse potential of theopioids.

CNS disorders are a type of neurological disorder. CNS disorders can bedrug induced; can be attributed to genetic predisposition, infection ortrauma; or can be of unknown etiology. CNS disorders compriseneuropsychiatric disorders, neurological diseases and mental illnesses;and include neurodegenerative diseases, behavioral disorders, cognitivedisorders and cognitive affective disorders. There are several CNSdisorders whose clinical manifestations have been attributed to CNSdysfunction (i.e., disorders resulting from inappropriate levels ofneurotransmitter release, inappropriate properties of neurotransmitterreceptors, and/or inappropriate interaction between neurotransmittersand neurotransmitter receptors). Several CNS disorders can be attributedto a deficiency of choline, dopamine, norepinephrine and/or serotonin.Relatively common CNS disorders include pre-senile dementia (early-onsetAlzheimer's disease), senile dementia (dementia of the Alzheimer'stype), micro-infarct dementia, AIDS-related dementia, Creutzfeld-Jakobdisease, Pick's disease, Parkinsonism including Parkinson's disease,Lewy body dementia, progressive supranuclear palsy, Huntington's chorea,tardive dyskinesia, hyperkinesia, mania, attention deficit disorder,anxiety, dyslexia, schizophrenia, depression, obsessive-compulsivedisorders, and Tourette's syndrome. Senile dementia of the Alzheimer'stype (SDAT) is a debilitating neurodegenerative disease, mainlyafflicting the elderly, characterized by a progressive intellectual andpersonality decline, as well as a loss of memory, perception, reasoning,orientation, and judgment. One feature of the disease is an observeddecline in the function of cholinergic systems, and specifically, asevere depletion of cholinergic neurons (i.e., neurons that releaseacetylcholine, which is believed to be a neurotransmitter involved inlearning and memory mechanisms). See, for example, Jones et al., Intern.J. Neurosci. 50:147 (1990); Perry, Br. Med. Bull. 42:63 (1986); andSitaram et al., Science 201:274 (1978). It has been observed thatnicotinic acetylcholine receptors, which bind nicotine and othernicotinic agonists with high affinity, are depleted during theprogression of SDAT. See Giacobini, J. Neurosci. Res. 27:548 (1990) andBaron, Neurology 36:1490 (1986). As such, it would seem desirable toprovide therapeutic compounds that either directly modulate (forexample, that directly activate) nicotinic receptors in place ofacetylcholine or act to minimize the loss of those nicotinic receptors.

Certain attempts have been made to treat SDAT. For example, nicotine hasbeen suggested to possess an ability to activate nicotinic cholinergicreceptors upon acute administration, and to elicit an increase in thenumber of such receptors upon chronic administration to animals. See,for example, Rowell, Adv. Behav. Biol. 31:191 (1987) and Marks, J.Pharmacol. Exp. Ther. 226:817 (1983). It also has been proposed thatnicotine can act directly to elicit the release of acetylcholine inbrain tissue, to improve cognitive functions, and to enhance attention.See Rowell et al., J. Neurochem. 43:1593 (1984); Sherwood, HumanPsychopharm. 8:155 (1993); **HN: START HERE Hodges et al., Bio. of Nic.Edit. by Lippiello et al., p. 157 (1991); Sahakian et al., Br. J. Psych.154:797 (1989); and U.S. Pat. Nos. 4,965,074 to Leeson and 5,242,935 toLippiello et al. Other methods for treating SDAT have been proposed,including U.S. Pat. Nos. 5,212,188 to Caldwell et al. and 5,227,391 toCaldwell et al., European Patent Application No. 588,917 and PCT WO96/30372. Another proposed treatment for SDAT is COGNEX®, which is acapsule containing tacrine hydrochloride, available from Parke-DavisDivision of Warner-Lambert Company, which reportedly preserves existingacetylcholine levels in patients treated therewith.

Parkinson's disease (PD) is a debilitating neurodegenerative disease,presently of unknown etiology, characterized by tremors and muscularrigidity. A feature of the disease appears to involve the degenerationof dopaminergic neurons (i.e., which secrete dopamine). One symptom ofthe disease has been observed to be a concomitant loss of nicotinicreceptors which are associated with such dopaminergic neurons, and whichare believed to modulate the process of dopamine secretion. See Rinne etal., Brain Res. 54:167 (1991) and Clark et al., Br. J. Pharm. 85:827(1985). It also has been proposed that nicotine can ameliorate thesymptoms of PD, as discussed in Smith et al., Rev. Neurosci. 3(1):25(1992).

Certain attempts have been made to treat PD. One proposed treatment forPD is SINEMET CR®, which is a sustained-release tablet containing amixture of carbidopa and levodopa, available from The DuPont MerckPharmaceutical Co. Another proposed treatment for PD is ELDEPRYL®, whichis a tablet containing selegiline hydrochloride, available from SomersetPharmaceuticals, Inc. Another proposed treatment for PD is PARLODEL®,which is a tablet containing bromocriptine mesylate, available fromSandoz Pharmaceuticals Corporation. Another method for treating PD and avariety of other neurodegenerative diseases has been proposed in U.S.Pat. No. 5,210,076 to Berliner et al.

Tourette's syndrome (TS) is an autosomal dominant neuropsychiatricdisorder characterized by a range of neurological and behavioralsymptoms. Typical symptoms include (i) the onset of the disorder beforethe age of 21 years, (ii) multiple motor and phonic tics although notnecessarily concurrently, (iii) variance in the clinical phenomenologyof the tics, and (iv) occurrence of quasi-daily tics throughout a periodof time exceeding a year. Motor tics generally include eye blinking,head jerking, shoulder shrugging and facial grimacing; while phonic orvocal tics include throat clearing, sniffling, yelping, tongue clickingand uttering words out of context. The pathophysiology of TS presentlyis unknown, however it is believed that neurotransmission dysfunction isimplicated with the disorder. For further discussion, seeCalderon-Gonzalez et al., Intern. Pediat. 8(2):176 (1993) and OxfordTextbook of Medicine, Weatherall et al., eds., p. 218 (1987).

It has been proposed that nicotine pharmacology is beneficial insuppressing the symptoms associated with TS. See Devor et al., TheLancet 8670: 1046 (1989); Jarvik, Brit. J. of Addic. 86: 571 (1991);McConville et al., Am. J. Psychiatry 148(6): 793 (1991); Newhouse etal., Brit. J. Addic. 86: 521 (1991); McConville et al., Biol. Psychiatry31: 832 (1992); and Sanberg et al., Proceedings from Intl. Symp. Nic.S39 (1994). It also has been proposed to treat TS using HALDOL®, whichis haloperidol available from McNeil Pharmaceutical; CATAPRES®, which isclonidine available from Boehringer Ingelheim Pharmaceuticals, Inc.,ORAP®, which is pimozide available from Gate Pharmaceuticals; PROLIXIN®,which is fluphenazine available from Apothecon Division of Bristol-MyersSquibb Co.; and KLONOPIN®, which is clonazepam available fromHoffmann-LaRoche Inc.

Attention deficit disorder (ADD) is a disorder that affects mainlychildren, although ADD can affect adolescents and adults. See Vinson,Arch. Fam. Med. 3(5): 445 (1994); Hechtman, J. Psychiatry Neurosci.19(3): 193 (1994); Faraone et al., Biol. Psychiatry 35(6): 398 (1994)and Malone et al., J. Child Neurol. 9(2): 181 (1994). Subjects sufferingfrom the disorder typically have difficulty concentrating, listening,learning and completing tasks; and are restless, fidgety, impulsive, andeasily distracted. Attention deficit disorder with hyperactivity (ADHD)includes the symptoms of ADD as well as a high level of activity (e.g.,restlessness and movement). Attempts to treat ADD have involvedadministration of DEXEDRINE®, which is a sustained release capsulecontaining dextroamphetamine sulfate, available from SmithKline BeechamPharmaceuticals; RITALIN®, which is a tablet containing methylphenidatehydrochloride, available from Ciba Pharmaceutical Company; and CYLERT®,which is a tablet containing premoline, available from AbbottLaboratories. In addition, it has been reported that administration ofnicotine to an individual improves that individual's selective andsustained attention. See Warburton et al., Cholinergic Control ofCognitive Resources, Europsychobiology, Mendlewicz et al., eds., p. 43(1993) and Levin et al., Psychopharmacology 123:55 (1996).

Schizophrenia is characterized by psychotic symptoms includingdelusions, catatonic behavior, and prominent hallucinations, andultimately results in a profound decline in the psychosocial affect ofthe subject suffering therefrom. Traditionally, schizophrenia has beentreated with KLONOPIN®, which is available as a tablet containingclonezepam, available from Hoffmann-LaRoche Inc.; THORAZINE®, which isavailable as a tablet containing chlorpromazine, available fromSmithKline Beecham Pharmaceuticals; and CLORAZIL®, which is a tabletcontaining clozapine, available from Sandoz Pharmaceuticals. Suchneuroleptics are believed to be effective as a result of interactionwith the dopaminergic pathways of the CNS. In addition, a dopaminergicdysfunction possessed by individuals suffering from schizophrenia hasbeen proposed. See Lieberman et al., Schizophr. Bull. 19:371 (1993) andGlassman, Amer. J. Psychiatry 150:546 (1993). Nicotine has been proposedto be effective in modulating neurotransmitter dysfunction associatedwith schizophrenia. See Merriam et al., Psychiatr. Annals 23:171 (1993)and Adler et al., Biol. Psychiatry 32:607 (1992). See also Freedman etal., Proc. Natl. Acad. Sci. 94:587 (1997).

It would be desirable to provide a useful method for the prevention andtreatment of a condition or disorder by administering a nicotiniccompound to a patient susceptible to or suffering from such a conditionor disorder. It would be highly beneficial to provide individualssuffering from certain disorders (e.g., CNS diseases) with interruptionof the symptoms of those disorders by the administration of apharmaceutical composition containing an active ingredient havingnicotinic pharmacology which has a beneficial effect (e.g., upon thefunctioning of the CNS), but does not provide any significant associatedside effects. It would be highly desirable to provide a pharmaceuticalcomposition incorporating a compound that interacts with nicotinicreceptors, such as those that have the potential to affect thefunctioning of the CNS, and methods of treatment using the compounds andcompositions. The present invention provides such compounds,compositions, and methods.

There exist subtypes of nAChRs in both the central and peripheralnervous systems, but the distribution of subtypes is heterogeneous. Forinstance, the subtypes which are predominant in vertebrate brain areα4β2, α7, and α3β2, whereas those which predominate at the autonomicganglia are α3β4 and those of neuromuscular junction are α1β1δγ andα1β1εε (see for instance Dwoskin et al., Exp. Opin. Ther. Patents 10:1561 (2000) and Schmitt and Bencherif, Annual Reports in Med. Chem. 35:41 (2000)). A limitation of some nicotinic compounds is that they elicitvarious undesirable pharmacological effects because of their interactionwith nAChRs in peripheral tissues (for example, by stimulating muscleand ganglionic nAChR subtypes). It would be desirable to have compounds,compositions and methods for preventing and/or treating variousconditions or disorders (e.g., CNS disorders), including alleviating thesymptoms of these disorders, where the compounds exhibit nicotinicpharmacology with a beneficial effect on the CNS nAChRs (e.g., upon thefunctioning of the CNS), but without significant associated effects onthe peripheral nAChRs (compounds specific for CNS nAChRs, withoutsignificant effects on cardiovascular and/or skeletal muscle receptorsites).

Dopamine release is believed to be associated with the physiological“reward” associated with consumption of these substances of addiction.Modulation of dopamine release has been proposed for use in treatingaddiction. Modulation of the α4β2 receptor is one way to modulatedopamine release, and may be at least part of the mechanism by whichmecamylamine is effective at treating drug addiction. However, it may bedesirable in some instances to modulate dopamine release withoutantagonizing α4β2 activity. Thus, the availability of a variety ofligands that bind with high affinity and selectivity for receptors otherthan α4β2, and that modulate dopamine release, are of interest.

A limitation of some nicotinic compounds is that they are associatedwith various undesirable side effects, for example, by stimulatingmuscle and ganglionic receptors. It would be desirable to havecompounds, compositions and methods for treating and/or preventingcentral nervous system disorders, and treating and/or preventing drugaddiction, promoting smoking cessation, and inhibiting obesity, wherethe compounds exhibit pharmacology with a beneficial effect (e.g.,inhibition of dopamine secretion), but without significant associatedside effects. The present invention provides such compounds,compositions and methods.

SUMMARY OF THE INVENTION

Compounds and methods for preventing and/or treating conditions ordisorders, such as CNS disorders, are disclosed. The methods involveadministering to a subject an effective amount of aheteroaryl-substituted azabicycloalkene or azabicycloalkane, includingenantiomerically enriched forms thereof. Also disclosed arepharmaceutical compositions comprising an effective amount of thesecompounds and the methods of preparing the compounds. The compositionsincorporate a compound which, when employed in effective amounts, hasthe capability of interacting with relevant nAChRs of a subject, andhence has the capability of acting as a therapeutic agent in theprevention or treatment of conditions or disorders. Preferredpharmaceutical compositions comprise novel compounds of the presentinvention.

The pharmaceutical compositions are useful for preventing and/ortreating conditions or disorders, such as CNS disorders and pain. Thepharmaceutical compositions provide therapeutic benefit to individualssuffering from such conditions or disorders and exhibiting clinicalmanifestations of such conditions or disorders. The compounds,administered with the pharmaceutical compositions, can be employed ineffective amounts to (i) exhibit nicotinic pharmacology and affectrelevant nicotinic receptors sites (e.g., act as a pharmacologicalmodulators at nicotinic receptors), and (ii) modulate neurotransmittersecretion, and hence prevent or suppress the symptoms associated withthose diseases. In addition, the compounds have the potential to (i)increase the number of nAChRs of the brain of the patient, (ii) exhibitneuroprotective effects and (iii) when employed in effective amounts,not cause appreciable adverse side effects (e.g., significant increasesin blood pressure and heart rate, significant negative effects upon thegastro-intestinal tract, and significant effects upon skeletal muscle).

The compounds and pharmaceutical compositions including them arebelieved to be safe and effective with regards to prevention andtreatment of various conditions or disorders.

In one embodiment, the compounds and pharmaceutical compositionsincluding them can also be used in methods of treating nicotineaddiction, drug addiction, and/or obesity. In this embodiment, thecompounds function by decreasing dopamine release, without significantlyaffecting the α4β2 receptor. Decreased dopamine release results in adecreased physiological “reward” associated with administration ofnicotine or illicit drugs, and thus helps overcome addiction.

The foregoing and other aspects of the present invention are explainedin detail in the detailed description and examples set forth below.

DETAILED DESCRIPTION OF THE INVENTION

The compounds, compositions and methods described herein will be betterunderstood with reference to the following preferred embodiments. Thefollowing definitions will be useful in defining the scope of theinvention:

As used herein, “aromatic” refers to 3 to 10, preferably 5 and6-membered ring aromatic and heteroaromatic rings.

As used herein, “aromatic group-containing species” refer to moietiesthat are or include an aromatic group. Accordingly, phenyl and benzylmoieties are included in this definition, as both are or include anaromatic group.

As used herein, C1-6 alkyl radicals (lower alkyl radicals) contain from1 to 6 carbon atoms in a straight or branched chain, and also includeC3-6 cycloalkyl moieties and alkyl radicals that contain C3-6 cycloalkylmoieties.

As used herein, C1-6 alkoxy radicals contain from 1 to 6 carbon atoms ina straight or branched chain, and also include C3-6 cycloalkoxy radicalsand alkoxy radicals that contain C3-6 cycloalkyl moieties.

As used herein, aryl radicals are selected from phenyl, naphthyl andindenyl.

As used herein, heteroaryl radicals contain from 3 to 10 members,preferably 5 or 6 members, including one or more heteroatoms selectedfrom oxygen, sulfur and nitrogen. Examples of suitable 5-membered ringheteroaryl moieties include furyl, thienyl, pyrrolyl, imidazolyl,oxazolyl, thiazolyl, isoxazolyl, isothiazolyl, tetrazolyl, triazolyl,and pyrazolyl. Examples of suitable 6-membered ring heteroaryl moietiesinclude pyridinyl, pyrimidinyl, pyrazinyl, and pyridazinyl, of whichpyridinyl and pyrimidinyl are preferred.

As used herein, halogen is chlorine, iodine, fluorine or bromine.

As used herein, heterocyclyl radicals contain from 3 to 10 membersincluding one or more heteroatoms selected from oxygen, sulfur andnitrogen. Examples of suitable heterocyclyl moieties include, but arenot limited to, piperidinyl, morpholinyl, pyrrolidinyl, imidazolidinyl,pyrazolidinyl, isothiazolidinyl, thiazolidinyl, isoxazolidinyl,oxazolidinyl, piperazinyl, oxanyl (tetrahydropyranyl), and oxolanyl(tetrahydrofuranyl).

As used herein, cycloalkyl radicals contain from 3 to 8 carbon atoms.Examples of suitable cycloalkyl radicals include, but are not limitedto, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, andcyclooctyl.

Examples of suitable pharmaceutically acceptable salts include inorganicacid addition salts such as chloride, bromide, sulfate, phosphate, andnitrate; organic acid addition salts such as acetate, galactarate,propionate, succinate, lactate, glycolate, malate, tartrate, citrate,maleate, fumarate, methanesulfonate, p-toluenesulfonate, and ascorbate;salts with acidic amino acid such as aspartate and glutamate; alkalimetal salts such as sodium salt and potassium salt; alkaline earth metalsalts such as magnesium salt and calcium salt; ammonium salt; organicbasic salts such as trimethylamine salt, triethylamine salt, pyridinesalt, picoline salt, dicyclohexylamine salt, andN,N′-dibenzylethylenediamine salt; and salts with basic amino acid suchas lysine salt and arginine salt. The salts may be in some caseshydrates or ethanol solvates. Representative salts are provided asdescribed in U.S. Pat. Nos. 5,597,919 to Dull et al., 5,616,716 to Dullet al. and 5,663,356 to Ruecroft et al.

As used herein, an “agonist” is a substance that stimulates its bindingpartner, typically a receptor. Stimulation is defined in the context ofthe particular assay, or may be apparent in the literature from adiscussion herein that makes a comparison to a factor or substance thatis accepted as an “agonist” or an “antagonist” of the particular bindingpartner under substantially similar circumstances as appreciated bythose of skill in the art. Stimulation may be defined with respect to anincrease in a particular effect or function that is induced byinteraction of the agonist or partial agonist with a binding partner andcan include allosteric effects.

As used herein, an “antagonist” is a substance that inhibits its bindingpartner, typically a receptor. Inhibition is defined in the context ofthe particular assay, or may be apparent in the literature from adiscussion herein that makes a comparison to a factor or substance thatis accepted as an “agonist” or an “antagonist” of the particular bindingpartner under substantially similar circumstances as appreciated bythose of skill in the art. Inhibition may be defined with respect to adecrease in a particular effect or function that is induced byinteraction of the antagonist with a binding partner, and can includeallosteric effects.

As used herein, a “partial agonist” is a substance that provides a levelof stimulation to its binding partner that is intermediate between thatof a full or complete antagonist and an agonist defined by any acceptedstandard for agonist activity. It will be recognized that stimulation,and hence, inhibition is defined intrinsically for any substance orcategory of substances to be defined as agonists, antagonists, orpartial agonists.

As used herein, a “partial antagonist” is a substance that provides alevel of inhibition to its binding partner that is intermediate betweenthat of a full or complete antagonist and an inactive ligand.

As used herein, “intrinsic activity”, or “efficacy,” relates to somemeasure of biological effectiveness of the binding partner complex. Withregard to receptor pharmacology, the context in which intrinsic activityor efficacy should be defined will depend on the context of the bindingpartner (e.g., receptor/ligand) complex and the consideration of anactivity relevant to a particular biological outcome. For example, insome circumstances, intrinsic activity may vary depending on theparticular second messenger system involved. See Hoyer and Boddeke,Trends Pharmacol Sci. 14(7): 270 (1993). Where such contextuallyspecific evaluations are relevant, and how they might be relevant in thecontext of the present invention, will be apparent to one of ordinaryskill in the art.

As used herein, modulation of a receptor includes agonism, partialagonism, antagonism, partial antagonism, or inverse agonism of areceptor.

As used herein, neurotransmitters whose release is modulated by thecompounds described herein include, but are not limited to,acetylcholine, dopamine, norepinephrine, serotonin, and glutamate, andthe compounds described herein function as agonists or partial agonistsat one or more of the Central Nervous System (CNS) nAChRs.

I. COMPOUNDS

The present invention relates to compounds having general Formulas 1 and2,

wherein k, m, n, and p are individually 0, 1, 2 or 3, provided that,when k+p=1, m or n or both must be greater than 0;R is hydrogen, lower alkyl, arylalkyl (including heteroarylalkyl), acyl,alkoxycarbonyl, or aryloxycarbonyl;Ar is heteroaryl, either monocyclic or polycyclic, optionallysubstituted at any position with a substituent Z as defined below, withthe proviso that in the compounds of Formula 2, when the azabicyclicring is a 6-azabicyclo[3.2.1]octane, Ar is not pyridine or substitutedpyridine;Z is a non-hydrogen substituent species (attached at a carbon atom ofthe azabicycle) chosen from among alkyl, substituted alkyl, alkenyl,substituted alkenyl, heterocyclyl, substituted heterocyclyl, cycloalkyl,substituted cycloalkyl, aryl (including heteroaryl), substituted aryl(including heteroaryl), alkylaryl, substituted alkylaryl, arylalkyl,substituted arylalkyl, halo (e.g., F, Cl, Br, or I), —OR′, —NR′R″, —CF₃,—CN, —NO₂, —C₂R′, —SR′, —N₃, —C(═O)NR′R″, —NR′C(═O)R″, —C(═O)R′,—C(═O)OR′, —OC(═O)R′, —O(CR′R″)_(r)C(═O)R′, —O(CR′R″)_(r)NR″C(═O)R′,—O(CR′R″)_(r)NR″SO₂R′, —OC(═O)NR′R″, —NR′C(═O)OR″, —SO₂R′, —SO₂NR′R″,and —NR′SO₂R″, where R′ and R″ are individually hydrogen, lower alkyl(e.g., straight chain or branched alkyl including C₁-C₆, preferablyC₁-C₄, such as methyl, ethyl, or isopropyl), cycloalkyl, heterocyclyl,aryl, or arylalkyl (such as benzyl), and r is an integer from 1 to 6. R′and R″ can combine to form a cyclic functionality. The term“substituted” as applied to alkyl, aryl (including heteroaryl),cycloalkyl and the like refers to the substituents described above,starting with halo and ending with —NR′SO₂R″; and j is 0, 1, or 2.

It is preferred that Ar be a 5-membered or 6-membered heteroaromaticring. Thus Ar can be depicted as follows:

wherein each of X, X′, X″, X′″, and X″″ is individually nitrogen,nitrogen bonded to oxygen (e.g., an N-oxide or N—O functionality), orcarbon bonded to H or a non-hydrogen substituent species (such as asubstituent species Z as defined herein). No more than three of X, X′,X″, X′″, and X″″ are nitrogen or nitrogen bonded to oxygen, and it ispreferred that only one or two of X, X′, X″, X′″, and X″″ be nitrogen ornitrogen bonded to oxygen. In addition, it is highly preferred that notmore than one of X, X′, X″, X′″, and X″″ be nitrogen bonded to oxygen;and it is preferred that if one of those species is nitrogen bonded tooxygen, that species is X′″. Most preferably, X′″ is nitrogen. Incertain preferred circumstances, both X′ and X′″ are nitrogen.Typically, X, X″, and X″″ are carbon bonded to a substituent species,and it is typical that the substituent species at X, X″, and X″″ arehydrogen. For certain other preferred compounds where X′″ is carbonbonded to a substituent species such as hydrogen, X and X′ are bothnitrogen. In certain other preferred compounds where X′ is carbon bondedto a substituent species such as hydrogen, X and X′″ are both nitrogen.

When the value of k+p (as defined above) is greater than 0 (zero), Arcan also be a five 5-membered heteroaromatic ring, such as pyrrole,furan, thiophene, isoxazole, isothiazole, oxazole, thiazole, pyrazole,1,2,4-oxadiazole, 1,3,4-oxadiazole, or 1,2,4-triazole. Other examples ofsuch rings are described in U.S. Pat. No. 6,022,868 to Olesen et al.,the contents of which are incorporated herein by reference in theirentirety. Thus, another way of depicting Ar is as follows:

wherein Y and Y″ are individually nitrogen, nitrogen bonded to asubstituent species, oxygen, sulfur or carbon bonded to a substituentspecies, and Y′ and Y′″ are nitrogen or carbon bonded to a substituentspecies. The dashed lines indicate that the bonds (between Y and Y′ andbetween Y′ and Y″) can be either single or double bonds. However, whenthe bond between Y and Y′ is a single bond, the bond between Y′ and Y″must be a double bond and vice versa. In cases in which Y or Y″ isoxygen or sulfur, only one of Y and Y″ is either oxygen or sulfur. Atleast one of Y, Y′, Y″, and Y′″ must be oxygen, sulfur, nitrogen, ornitrogen bonded to a substituent species. It is preferred that no morethan three of Y, Y′, Y″, and Y′″ be oxygen, sulfur, nitrogen, ornitrogen bonded to a substituent species. It is further preferred thatat least one, but no more than three, of Y, Y′, Y″, and Y′″ be nitrogen.However, when m+n=0, Ar is neither 1,2,5-oxadiazole nor1,2,5-thiadiazole nor a substituted version thereof.

Substituent species associated with any of X, X′, X″, X′″, X″″, Y, Y′,Y″, and Y′″ (when any is carbon bonded to a substituent species),typically have a sigma m value between about −0.3 and about 0.75,frequently between about −0.25 and about 0.6; and each sigma m valueindividually can be 0 or not equal to zero; as determined in accordancewith Hansch et al., Chem. Rev. 91:165 (1991).

Examples of suitable substituent species associated with any of X, X′,X″, X′″, X″″, Y, Y′, Y″, and Y′″ (when any is carbon bonded to asubstituent species), include hydrogen, alkyl, substituted alkyl,alkenyl, substituted alkenyl, heterocyclyl, substituted heterocyclyl,cycloalkyl, substituted cycloalkyl, aryl (including heteroaryl),substituted aryl (including heteroaryl), alkylaryl, substitutedalkylaryl, arylalkyl, substituted arylalkyl, halo (e.g., F, Cl, Br, orI), —OR′, —NR′R″, —CF₃, —CN, —NO₂, —C₂R′, —SR′, —N₃, —C(═O)NR′R″,—NR′C(═O)R″, —C(═O)R′, —C(═O)OR′, —OC(═O)R′, —O(CR′R″)_(r)C(═O)R′,—O(CR′R″)_(r)NR″C(═O)R′, —O(CR′R″)_(r)NR″SO₂R′, —OC(═O)NR′R″,—NR′C(═O)OR″, —SO₂R′, —SO₂NR′R″, and —NR′SO₂R″, where R′ and R″ areindividually hydrogen, lower alkyl (e.g., straight chain or branchedalkyl including C₁-C₆, preferably C₁-C₄, such as methyl, ethyl, orisopropyl), cycloalkyl, heterocyclyl, aryl, or arylalkyl (such asbenzyl), and r is an integer from 1 to 6. R′ and R″ can combine to forma cyclic functionality. The term “substituted” as applied to alkyl, aryl(including heteroaryl), cycloalkyl and the like refers to thesubstituents described above, starting with halo and ending with—NR′SO₂R″.

Examples of suitable Ar groups include 3-pyridinyl (unsubstituted orsubstituted in the 5 and/or 6 position(s) with any of the aforementionedsubstituents), 5-pyrimidinyl (unsubstituted or substituted in the 2position with any of the aforementioned substituents), 2-pyrazinyl and3-pyridazinyl, 4 and 5-isoxazolyl, 4 and 5-isothiazolyl, 5-oxazolyl,5-thiazolyl, 5-(1,2,4-oxadiazolyl), 2-(1,3,4-oxadiazolyl), or3-(1,2,4-triazolyl).

Adjacent substituents of X, X′, X″, X′″, X″″, Y, Y′, Y″, and Y′″ (whensubstituents are present) can combine to form one or more saturated orunsaturated, substituted or unsubstituted carbocyclic or heterocyclicrings containing, but not limited to, ether, acetal, ketal, amine,ketone, lactone, lactam, carbamate, or urea functionalities.

The compounds can occur in stereoisomeric forms, including both singleenantiomers and racemic mixtures of such compounds, as well as mixturesof varying degrees of enantiomeric excess. Compounds with a plane ofsymmetry, such that the compound is not chiral, can be preferred forease of preparation.

The compounds can be in a free base form or in a salt form (e.g., aspharmaceutically acceptable salts). Examples of suitablepharmaceutically acceptable salts have been listed above. Representativesalts are provided as described in U.S. Pat. Nos. 5,597,919 to Dull etal., 5,616,716 to Dull et al. and 5,663,356 to Ruecroft et al., thedisclosures of which are incorporated herein by reference in theirentirety. The compounds of the present invention are nitrogenous bases,and, in some cases, are capable of forming quaternary ammonium salts byreaction with alkylating agents (e.g., alkyl halides). Such quaternaryammonium salts are also compounds of the present invention.

Specific sub-structures falling within the scope of Formulas 1 and 2 areshown below:

where the hashed bond indicates the optional presence of a double bond(and wherein the presence of adjacent hashed bonds indicates that one(but not both) of the hashed bonds can be a double bond), X′ is N, orcarbon bonded to H or a substituent Z as defined above, and R, Z, and jare defined as above.

Within the group of structures shown above as falling within Formulas 1and 2, the following group of structures is a preferred subset:

where R, Z and j are as defined above, and the ashed bond indicates theoptional presence of a double bond.

Specific compounds within this subset include the following:

Representative compounds of the present invention include the following:

-   2-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene,-   3-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene,-   3-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene,-   4-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene,-   6-(3-pyridinyl)-2-azabicyclo[3.2.1]oct-6-ene,-   7-(3-pyridinyl)-2-azabicyclo[3.2.1]oct-6-ene,-   6-(3-pyridinyl)-3-azabicyclo[3.2.1]oct-6-ene,-   6-(3-pyridinyl)-2-azabicyclo[3.3.1]non-6-ene,-   7-(3-pyridinyl)-2-azabicyclo[3.3.1]non-6-ene,-   6-(3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,-   7-(3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,-   7-(3-pyridinyl)-2-azabicyclo[3.3.1]non-7-ene,-   8-(3-pyridinyl)-2-azabicyclo[3.3.1]non-7-ene,-   4-(3-pyridinyl)-8-azabicyclo[5.1.1]non-3-ene,-   3-(3-pyridinyl)-8-azabicyclo[4.3.1]dec-3-ene,-   8-(3-pyridinyl)-4-azabicyclo[5.2.1]dec-8-ene,-   9-(3-pyridinyl)-4-azabicyclo[5.3.1]undec-8-ene,-   6-(3-pyridinyl)-2-azabicyclo[3.2.1]octane,-   7-(3-pyridinyl)-2-azabicyclo[3.2.1]octane,-   6-(3-pyridinyl)-3-azabicyclo[3.2.1]octane,-   6-(3-pyridinyl)-2-azabicyclo[3.3.1]nonane,-   7-(3-pyridinyl)-2-azabicyclo[3.3.1]nonane,-   8-(3-pyridinyl)-2-azabicyclo[3.3.1]nonane,-   6-(3-pyridinyl)-3-azabicyclo[3.3.1]nonane,-   7-(3-pyridinyl)-3-azabicyclo[3.3.1]nonane,-   4-(3-pyridinyl)-8-azabicyclo[5.1.1]nonane,-   3-(3-pyridinyl)-8-azabicyclo[4.3.1]decane,-   8-(3-pyridinyl)-4-azabicyclo[5.2.1]decane,-   and 9-(3-pyridinyl)-4-azabicyclo[5.3.1]undecane.

Further representative compounds of the present invention include thefollowing:

-   2-(5-methoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene,-   3-(5-methoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene,-   3-(5-methoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene,-   4-(5-methoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene,-   6-(5-methoxy-3-pyridinyl)-2-azabicyclo[3.2.1]oct-6-ene,-   7-(5-methoxy-3-pyridinyl)-2-azabicyclo[3.2.1]oct-6-ene,-   6-(5-methoxy-3-pyridinyl)-3-azabicyclo[3.2.1]oct-6-ene,-   6-(5-methoxy-3-pyridinyl)-2-azabicyclo[3.3.1]non-6-ene,-   7-(5-methoxy-3-pyridinyl)-2-azabicyclo[3.3.1]non-6-ene,-   6-(5-methoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,-   7-(5-methoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,-   7-(5-methoxy-3-pyridinyl)-2-azabicyclo[3.3.1]non-7-ene,-   8-(5-methoxy-3-pyridinyl)-2-azabicyclo[3.3.1]non-7-ene,-   4-(5-methoxy-3-pyridinyl)-8-azabicyclo[5.1.1]non-3-ene,-   3-(5-methoxy-3-pyridinyl)-8-azabicyclo[4.3.1]dec-3-ene,-   8-(5-methoxy-3-pyridinyl)-4-azabicyclo[5.2.1]dec-8-ene,-   9-(5-methoxy-3-pyridinyl)-4-azabicyclo[5.3.1]undec-8-ene,-   6-(5-methoxy-3-pyridinyl)-2-azabicyclo[3.2.1]octane,-   7-(5-methoxy-3-pyridinyl)-2-azabicyclo[3.2.1]octane,-   6-(5-methoxy-3-pyridinyl)-3-azabicyclo[3.2.1]octane,-   6-(5-methoxy-3-pyridinyl)-2-azabicyclo[3.3.1]nonane,-   7-(5-methoxy-3-pyridinyl)-2-azabicyclo[3.3.1]nonane,-   8-(5-methoxy-3-pyridinyl)-2-azabicyclo[3.3.1]nonane,-   6-(5-methoxy-3-pyridinyl)-3-azabicyclo[3.3.1]nonane,-   7-(5-methoxy-3-pyridinyl)-3-azabicyclo[3.3.1]nonane,-   4-(5-methoxy-3-pyridinyl)-8-azabicyclo[5.1.1]nonane,-   3-(5-methoxy-3-pyridinyl)-8-azabicyclo[4.3.1]decane,-   8-(5-methoxy-3-pyridinyl)-4-azabicyclo[5.2.1]decane,-   and 9-(5-methoxy-3-pyridinyl)-4-azabicyclo[5.3.1]undecane.

Further representative compounds of the present invention include thefollowing:

-   2-(6-methoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene,-   3-(6-methoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene,-   3-(6-methoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene,-   4-(6-methoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene,-   6-(6-methoxy-3-pyridinyl)-2-azabicyclo[3.2.1]oct-6-ene,-   7-(6-methoxy-3-pyridinyl)-2-azabicyclo[3.2.1]oct-6-ene,-   6-(6-methoxy-3-pyridinyl)-3-azabicyclo[3.2.1]oct-6-ene,-   6-(6-methoxy-3-pyridinyl)-2-azabicyclo[3.3.1]non-6-ene,-   7-(6-methoxy-3-pyridinyl)-2-azabicyclo[3.3.1]non-6-ene,-   6-(6-methoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,-   7-(6-methoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,-   7-(6-methoxy-3-pyridinyl)-2-azabicyclo[3.3.1]non-7-ene,-   8-(6-methoxy-3-pyridinyl)-2-azabicyclo[3.3.1]non-7-ene,-   4-(6-methoxy-3-pyridinyl)-8-azabicyclo[5.1.1]non-3-ene,-   3-(6-methoxy-3-pyridinyl)-8-azabicyclo[4.3.1]dec-3-ene,-   8-(6-methoxy-3-pyridinyl)-4-azabicyclo[5.2.1]dec-8-ene,-   9-(6-methoxy-3-pyridinyl)-4-azabicyclo[5.3.1]undec-8-ene,-   6-(6-methoxy-3-pyridinyl)-2-azabicyclo[3.2.1]octane,-   7-(6-methoxy-3-pyridinyl)-2-azabicyclo[3.2.1]octane,-   6-(6-methoxy-3-pyridinyl)-3-azabicyclo[3.2.1]octane,-   6-(6-methoxy-3-pyridinyl)-2-azabicyclo[3.3.1]nonane,-   7-(6-methoxy-3-pyridinyl)-2-azabicyclo[3.3.1]nonane,-   8-(6-methoxy-3-pyridinyl)-2-azabicyclo[3.3.1]nonane,-   6-(6-methoxy-3-pyridinyl)-3-azabicyclo[3.3.1]nonane,-   7-(6-methoxy-3-pyridinyl)-3-azabicyclo[3.3.1]nonane,-   4-(6-methoxy-3-pyridinyl)-8-azabicyclo[5.1.1]nonane,-   3-(6-methoxy-3-pyridinyl)-8-azabicyclo[4.3.1]decane,-   8-(6-methoxy-3-pyridinyl)-4-azabicyclo[5.2.1]decane,-   and 9-(6-methoxy-3-pyridinyl)-4-azabicyclo[5.3.1]undecane.

Further representative compounds of the present invention include thefollowing:

-   2-(5-isopropoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene,-   3-(5-isopropoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene,-   3-(5-isopropoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene,-   4-(5-isopropoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene,-   6-(5-isopropoxy-3-pyridinyl)-2-azabicyclo[3.2.1]oct-6-ene,-   7-(5-isopropoxy-3-pyridinyl)-2-azabicyclo[3.2.1]oct-6-ene,-   6-(5-isopropoxy-3-pyridinyl)-3-azabicyclo[3.2.1]oct-6-ene,-   6-(5-isopropoxy-3-pyridinyl)-2-azabicyclo[3.3.1]non-6-ene,-   7-(5-isopropoxy-3-pyridinyl)-2-azabicyclo[3.3.1]non-6-ene,-   6-(5-isopropoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,-   7-(5-isopropoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,-   7-(5-isopropoxy-3-pyridinyl)-2-azabicyclo[3.3.1]non-7-ene,-   8-(5-isopropoxy-3-pyridinyl)-2-azabicyclo[3.3.1]non-7-ene,-   4-(5-isopropoxy-3-pyridinyl)-8-azabicyclo[5.1.1]non-3-ene,-   3-(5-isopropoxy-3-pyridinyl)-8-azabicyclo[4.3.1]dec-3-ene,-   8-(5-isopropoxy-3-pyridinyl)-4-azabicyclo[5.2.1]dec-8-ene,-   9-(5-isopropoxy-3-pyridinyl)-4-azabicyclo[5.3.1]undec-8-ene,-   6-(5-isopropoxy-3-pyridinyl)-2-azabicyclo[3.2.1]octane,-   7-(5-isopropoxy-3-pyridinyl)-2-azabicyclo[3.2.1]octane,-   6-(5-isopropoxy-3-pyridinyl)-3-azabicyclo[3.2.1]octane,-   6-(5-isopropoxy-3-pyridinyl)-2-azabicyclo[3.3.1]nonane,-   7-(5-isopropoxy-3-pyridinyl)-2-azabicyclo[3.3.1]nonane,-   8-(5-isopropoxy-3-pyridinyl)-2-azabicyclo[3.3.1]nonane,-   6-(5-isopropoxy-3-pyridinyl)-3-azabicyclo[3.3.1]nonane,-   7-(5-isopropoxy-3-pyridinyl)-3-azabicyclo[3.3.1]nonane,-   4-(5-isopropoxy-3-pyridinyl)-8-azabicyclo[5.1.1]nonane,-   3-(5-isopropoxy-3-pyridinyl)-8-azabicyclo[4.3.1]decane,-   8-(5-isopropoxy-3-pyridinyl)-4-azabicyclo[5.2.1]decane,-   and 9-(5-isopropoxy-3-pyridinyl)-4-azabicyclo[5.3.1]undecane.

Further representative compounds of the present invention include thefollowing:

-   2-(5-phenoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene,-   3-(5-phenoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene,-   3-(5-phenoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene,-   4-(5-phenoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene,-   6-(5-phenoxy-3-pyridinyl)-2-azabicyclo[3.2.1]oct-6-ene,-   7-(5-phenoxy-3-pyridinyl)-2-azabicyclo[3.2.1]oct-6-ene,-   6-(5-phenoxy-3-pyridinyl)-3-azabicyclo[3.2.1]oct-6-ene,-   6-(5-phenoxy-3-pyridinyl)-2-azabicyclo[3.3.1]non-6-ene,-   7-(5-phenoxy-3-pyridinyl)-2-azabicyclo[3.3.1]non-6-ene,-   6-(5-phenoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,-   7-(5-phenoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,-   7-(5-phenoxy-3-pyridinyl)-2-azabicyclo[3.3.1]non-7-ene,-   8-(5-phenoxy-3-pyridinyl)-2-azabicyclo[3.3.1]non-7-ene,-   4-(5-phenoxy-3-pyridinyl)-8-azabicyclo[5.1.1]non-3-ene,-   3-(5-phenoxy-3-pyridinyl)-8-azabicyclo[4.3.1]dec-3-ene,-   8-(5-phenoxy-3-pyridinyl)-4-azabicyclo[5.2.1]dec-8-ene,-   9-(5-phenoxy-3-pyridinyl)-4-azabicyclo[5.3.1]undec-8-ene,-   6-(5-phenoxy-3-pyridinyl)-2-azabicyclo[3.2.1]octane,-   7-(5-phenoxy-3-pyridinyl)-2-azabicyclo[3.2.1]octane,-   6-(5-phenoxy-3-pyridinyl)-3-azabicyclo[3.2.1]octane,-   6-(5-phenoxy-3-pyridinyl)-2-azabicyclo[3.3.1]nonane,-   7-(5-phenoxy-3-pyridinyl)-2-azabicyclo[3.3.1]nonane,-   8-(5-phenoxy-3-pyridinyl)-2-azabicyclo[3.3.1]nonane,-   6-(5-phenoxy-3-pyridinyl)-3-azabicyclo[3.3.1]nonane,-   7-(5-phenoxy-3-pyridinyl)-3-azabicyclo[3.3.1]nonane,-   4-(5-phenoxy-3-pyridinyl)-8-azabicyclo[5.1.1]nonane,-   3-(5-phenoxy-3-pyridinyl)-8-azabicyclo[4.3.1]decane,-   8-(5-phenoxy-3-pyridinyl)-4-azabicyclo[5.2.1]decane,-   and 9-(5-phenoxy-3-pyridinyl)-4-azabicyclo[5.3.1]undecane.

Further representative compounds of the present invention include thefollowing:

-   2-(5-phenyl-3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene,-   3-(5-phenyl-3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene,-   3-(5-phenyl-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene,-   4-(5-phenyl-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene,-   6-(5-phenyl-3-pyridinyl)-2-azabicyclo[3.2.1]oct-6-ene,-   7-(5-phenyl-3-pyridinyl)-2-azabicyclo[3.2.1]oct-6-ene,-   6-(5-phenyl-3-pyridinyl)-3-azabicyclo[3.2.1]oct-6-ene,-   6-(5-phenyl-3-pyridinyl)-2-azabicyclo[3.3.1]non-6-ene,-   7-(5-phenyl-3-pyridinyl)-2-azabicyclo[3.3.1]non-6-ene,-   6-(5-phenyl-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,-   7-(5-phenyl-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,-   7-(5-phenyl-3-pyridinyl)-2-azabicyclo[3.3.1]non-7-ene,-   8-(5-phenyl-3-pyridinyl)-2-azabicyclo[3.3.1]non-7-ene,-   4-(5-phenyl-3-pyridinyl)-8-azabicyclo[5.1.1]non-3-ene,-   3-(5-phenyl-3-pyridinyl)-8-azabicyclo[4.3.1]dec-3-ene,-   8-(5-phenyl-3-pyridinyl)-4-azabicyclo[5.2.1]dec-8-ene,-   9-(5-phenyl-3-pyridinyl)-4-azabicyclo[5.3.1]undec-8-ene,-   6-(5-phenyl-3-pyridinyl)-2-azabicyclo[3.2.1]octane,-   7-(5-phenyl-3-pyridinyl)-2-azabicyclo[3.2.1]octane,-   6-(5-phenyl-3-pyridinyl)-3-azabicyclo[3.2.1]octane,-   6-(5-phenyl-3-pyridinyl)-2-azabicyclo[3.3.1]nonane,-   7-(5-phenyl-3-pyridinyl)-2-azabicyclo[3.3.1]nonane,-   8-(5-phenyl-3-pyridinyl)-2-azabicyclo[3.3.1]nonane,-   6-(5-phenyl-3-pyridinyl)-3-azabicyclo[3.3.1]nonane,-   7-(5-phenyl-3-pyridinyl)-3-azabicyclo[3.3.1]nonane,-   4-(5-phenyl-3-pyridinyl)-8-azabicyclo[5.1.1]nonane,-   3-(5-phenyl-3-pyridinyl)-8-azabicyclo[4.3.1]decane,-   8-(5-phenyl-3-pyridinyl)-4-azabicyclo[5.2.1]decane,-   and 9-(5-phenyl-3-pyridinyl)-4-azabicyclo[5.3.1]undecane.

Further representative compounds of the present invention include thefollowing:

-   2-(6-chloro-3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene,-   3-(6-chloro-3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene,-   3-(6-chloro-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene,-   4-(6-chloro-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene,-   6-(6-chloro-3-pyridinyl)-2-azabicyclo[3.2.1]oct-6-ene,-   7-(6-chloro-3-pyridinyl)-2-azabicyclo[3.2.1]oct-6-ene,-   6-(6-chloro-3-pyridinyl)-3-azabicyclo[3.2.1]oct-6-ene,-   6-(6-chloro-3-pyridinyl)-2-azabicyclo[3.3.1]non-6-ene,-   7-(6-chloro-3-pyridinyl)-2-azabicyclo[3.3.1]non-6-ene,-   6-(6-chloro-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,-   7-(6-chloro-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,-   7-(6-chloro-3-pyridinyl)-2-azabicyclo[3.3.1]non-7-ene,-   8-(6-chloro-3-pyridinyl)-2-azabicyclo[3.3.1]non-7-ene,-   4-(6-chloro-3-pyridinyl)-8-azabicyclo[5.1.1]non-3-ene,-   3-(6-chloro-3-pyridinyl)-8-azabicyclo[4.3.1]dec-3-ene,-   8-(6-chloro-3-pyridinyl)-4-azabicyclo[5.2.1]dec-8-ene,-   9-(6-chloro-3-pyridinyl)-4-azabicyclo[5.3.1]undec-8-ene,-   6-(6-chloro-3-pyridinyl)-2-azabicyclo[3.2.1]octane,-   7-(6-chloro-3-pyridinyl)-2-azabicyclo[3.2.1]octane,-   6-(6-chloro-3-pyridinyl)-3-azabicyclo[3.2.1]octane,-   6-(6-chloro-3-pyridinyl)-2-azabicyclo[3.3.1]nonane,-   7-(6-chloro-3-pyridinyl)-2-azabicyclo[3.3.1]nonane,-   8-(6-chloro-3-pyridinyl)-2-azabicyclo[3.3.1]nonane,-   6-(6-chloro-3-pyridinyl)-3-azabicyclo[3.3.1]nonane,-   7-(6-chloro-3-pyridinyl)-3-azabicyclo[3.3.1]nonane,-   4-(6-chloro-3-pyridinyl)-8-azabicyclo[5.1.1]nonane,-   3-(6-chloro-3-pyridinyl)-8-azabicyclo[4.3.1]decane,-   8-(6-chloro-3-pyridinyl)-4-azabicyclo[5.2.1]decane,-   and 9-(6-chloro-3-pyridinyl)-4-azabicyclo[5.3.1]undecane.

Further representative compounds of the present invention include thefollowing:

-   2-(5-pyrimidinyl)-6-azabicyclo[3.2.1]oct-2-ene,-   3-(5-pyrimidinyl)-6-azabicyclo[3.2.1]oct-2-ene,-   3-(5-pyrimidinyl)-6-azabicyclo[3.2.1]oct-3-ene,-   4-(5-pyrimidinyl)-6-azabicyclo[3.2.1]oct-3-ene,-   6-(5-pyrimidinyl)-2-azabicyclo[3.2.1]oct-6-ene,-   7-(5-pyrimidinyl)-2-azabicyclo[3.2.1]oct-6-ene,-   6-(5-pyrimidinyl)-3-azabicyclo[3.2.1]oct-6-ene,-   6-(5-pyrimidinyl)-2-azabicyclo[3.3.1]non-6-ene,-   7-(5-pyrimidinyl)-2-azabicyclo[3.3.1]non-6-ene,-   6-(5-pyrimidinyl)-3-azabicyclo[3.3.1]non-6-ene,-   7-(5-pyrimidinyl)-3-azabicyclo[3.3.1]non-6-ene,-   7-(5-pyrimidinyl)-2-azabicyclo[3.3.1]non-7-ene,-   8-(5-pyrimidinyl)-2-azabicyclo[3.3.1]non-7-ene,-   4-(5-pyrimidinyl)-8-azabicyclo[5.1.1]non-3-ene,-   3-(5-pyrimidinyl)-8-azabicyclo[4.3.1]dec-3-ene,-   8-(5-pyrimidinyl)-4-azabicyclo[5.2.1]dec-8-ene,-   9-(5-pyrimidinyl)-4-azabicyclo[5.3.1]undec-8-ene,-   2-(5-pyrimidinyl)-6-azabicyclo[3.2.1]octane,-   3-(5-pyrimidinyl)-6-azabicyclo[3.2.1]octane,-   4-(5-pyrimidinyl)-6-azabicyclo[3.2.1]octane,-   6-(5-pyrimidinyl)-2-azabicyclo[3.2.1]octane,-   7-(5-pyrimidinyl)-2-azabicyclo[3.2.1]octane,-   6-(5-pyrimidinyl)-3-azabicyclo[3.2.1]octane,-   6-(5-pyrimidinyl)-2-azabicyclo[3.3.1]nonane,-   7-(5-pyrimidinyl)-2-azabicyclo[3.3.1]nonane,-   8-(5-pyrimidinyl)-2-azabicyclo[3.3.1]nonane,-   6-(5-pyrimidinyl)-3-azabicyclo[3.3.1]nonane,-   7-(5-pyrimidinyl)-3-azabicyclo[3.3.1]nonane,-   4-(5-pyrimidinyl)-8-azabicyclo[5.1.1]nonane,-   3-(5-pyrimidinyl)-8-azabicyclo[4.3.1]decane,-   8-(5-pyrimidinyl)-4-azabicyclo[5.2.1]decane,-   and 9-(5-pyrimidinyl)-4-azabicyclo[5.3.1]undecane.

Further representative compounds of the present invention include thefollowing:

-   2-(3-pyrrolyl)-6-azabicyclo[3.2.1]oct-2-ene,-   3-(3-pyrrolyl)-6-azabicyclo[3.2.1]oct-2-ene,-   3-(3-pyrrolyl)-6-azabicyclo[3.2.1]oct-3-ene,-   4-(3-pyrrolyl)-6-azabicyclo[3.2.1]oct-3-ene,-   6-(3-pyrrolyl)-2-azabicyclo[3.2.1]oct-6-ene,-   7-(3-pyrrolyl)-2-azabicyclo[3.2.1]oct-6-ene,-   6-(3-pyrrolyl)-3-azabicyclo[3.2.1]oct-6-ene,-   6-(3-pyrrolyl)-2-azabicyclo[3.3.1]non-6-ene,-   7-(3-pyrrolyl)-2-azabicyclo[3.3.1]non-6-ene,-   6-(3-pyrrolyl)-3-azabicyclo[3.3.1]non-6-ene,-   7-(3-pyrrolyl)-3-azabicyclo[3.3.1]non-6-ene,-   7-(3-pyrrolyl)-2-azabicyclo[3.3.1]non-7-ene,-   8-(3-pyrrolyl)-2-azabicyclo[3.3.1]non-7-ene,-   4-(3-pyrrolyl)-8-azabicyclo[5.1.1]non-3-ene,-   3-(3-pyrrolyl)-8-azabicyclo[4.3.1]dec-3-ene,-   8-(3-pyrrolyl)-4-azabicyclo[5.2.1]dec-8-ene,-   9-(3-pyrrolyl)-4-azabicyclo[5.3.1]undec-8-ene,-   2-(3-pyrrolyl)-6-azabicyclo[3.2.1]octane,-   3-(3-pyrrolyl)-6-azabicyclo[3.2.1]octane,-   4-(3-pyrrolyl)-6-azabicyclo[3.2.1]octane,-   6-(3-pyrrolyl)-2-azabicyclo[3.2.1]octane,-   7-(3-pyrrolyl)-2-azabicyclo[3.2.1]octane,-   6-(3-pyrrolyl)-3-azabicyclo[3.2.1]octane,-   6-(3-pyrrolyl)-2-azabicyclo[3.3.1]nonane,-   7-(3-pyrrolyl)-2-azabicyclo[3.3.1]nonane,-   8-(3-pyrrolyl)-2-azabicyclo[3.3.1]nonane,-   6-(3-pyrrolyl)-3-azabicyclo[3.3.1]nonane,-   7-(3-pyrrolyl)-3-azabicyclo[3.3.1]nonane,-   4-(3-pyrrolyl)-8-azabicyclo[5.1.1]nonane,-   3-(3-pyrrolyl)-8-azabicyclo[4.3.1]decane,-   8-(3-pyrrolyl)-4-azabicyclo[5.2.1]decane,-   and 9-(3-pyrrolyl)-4-azabicyclo[5.3.1]undecane.

Further representative compounds of the present invention include thefollowing:

-   2-(4-pyrazolyl)-6-azabicyclo[3.2.1]oct-2-ene,-   3-(4-pyrazolyl)-6-azabicyclo[3.2.1]oct-2-ene,-   3-(4-pyrazolyl)-6-azabicyclo[3.2.1]oct-3-ene,-   4-(4-pyrazolyl)-6-azabicyclo[3.2.1]oct-3-ene,-   6-(4-pyrazolyl)-2-azabicyclo[3.2.1]oct-6-ene,-   7-(4-pyrazolyl)-2-azabicyclo[3.2.1]oct-6-ene,-   6-(4-pyrazolyl)-3-azabicyclo[3.2.1]oct-6-ene,-   6-(4-pyrazolyl)-2-azabicyclo[3.3.1]non-6-ene,-   7-(4-pyrazolyl)-2-azabicyclo[3.3.1]non-6-ene,-   6-(4-pyrazolyl)-3-azabicyclo[3.3.1]non-6-ene,-   7-(4-pyrazolyl)-3-azabicyclo[3.3.1]non-6-ene,-   7-(4-pyrazolyl)-2-azabicyclo[3.3.1]non-7-ene,-   8-(4-pyrazolyl)-2-azabicyclo[3.3.1]non-7-ene,-   4-(4-pyrazolyl)-8-azabicyclo[5.1.1]non-3-ene,-   3-(4-pyrazolyl)-8-azabicyclo[4.3.1]dec-3-ene,-   8-(4-pyrazolyl)-4-azabicyclo[5.2.1]dec-8-ene,-   9-(4-pyrazolyl)-4-azabicyclo[5.3.1]undec-8-ene,-   2-(4-pyrazolyl)-6-azabicyclo[3.2.1]octane,-   3-(4-pyrazolyl)-6-azabicyclo[3.2.1]octane,-   4-(4-pyrazolyl)-6-azabicyclo[3.2.1]octane,-   6-(4-pyrazolyl)-2-azabicyclo[3.2.1]octane,-   7-(4-pyrazolyl)-2-azabicyclo[3.2.1]octane,-   6-(4-pyrazolyl)-3-azabicyclo[3.2.1]octane,-   6-(4-pyrazolyl)-2-azabicyclo[3.3.1]nonane,-   7-(4-pyrazolyl)-2-azabicyclo[3.3.1]nonane,-   8-(4-pyrazolyl)-2-azabicyclo[3.3.1]nonane,-   6-(4-pyrazolyl)-3-azabicyclo[3.3.1]nonane,-   7-(4-pyrazolyl)-3-azabicyclo[3.3.1]nonane,-   4-(4-pyrazolyl)-8-azabicyclo[5.1.1]nonane,-   3-(4-pyrazolyl)-8-azabicyclo[4.3.1]decane,-   8-(4-pyrazolyl)-4-azabicyclo[5.2.1]decane,-   and 9-(4-pyrazolyl)-4-azabicyclo[5.3.1]undecane.

Further representative compounds of the present invention include thefollowing:

-   2-(4-isoxazolyl)-6-azabicyclo[3.2.1]oct-2-ene,-   3-(4-isoxazolyl)-6-azabicyclo[3.2.1]oct-2-ene,-   3-(4-isoxazolyl)-6-azabicyclo[3.2.1]oct-3-ene,-   4-(4-isoxazolyl)-6-azabicyclo[3.2.1]oct-3-ene,-   6-(4-isoxazolyl)-2-azabicyclo[3.2.1]oct-6-ene,-   7-(4-isoxazolyl)-2-azabicyclo[3.2.1]oct-6-ene,-   6-(4-isoxazolyl)-3-azabicyclo[3.2.1]oct-6-ene,-   6-(4-isoxazolyl)-2-azabicyclo[3.3.1]non-6-ene,-   7-(4-isoxazolyl)-2-azabicyclo[3.3.1]non-6-ene,-   6-(4-isoxazolyl)-3-azabicyclo[3.3.1]non-6-ene,-   7-(4-isoxazolyl)-3-azabicyclo[3.3.1]non-6-ene,-   7-(4-isoxazolyl)-2-azabicyclo[3.3.1]non-7-ene,-   8-(4-isoxazolyl)-2-azabicyclo[3.3.1]non-7-ene,-   4-(4-isoxazolyl)-8-azabicyclo[5.1.1]non-3-ene,-   3-(4-isoxazolyl)-8-azabicyclo[4.3.1]dec-3-ene,-   8-(4-isoxazolyl)-4-azabicyclo[5.2.1]dec-8-ene,-   9-(4-isoxazolyl)-4-azabicyclo[5.3.1]undec-8-ene,-   2-(4-isoxazolyl)-6-azabicyclo[3.2.1]octane,-   3-(4-isoxazolyl)-6-azabicyclo[3.2.1]octane,-   4-(4-isoxazolyl)-6-azabicyclo[3.2.1]octane,-   6-(4-isoxazolyl)-2-azabicyclo[3.2.1]octane,-   7-(4-isoxazolyl)-2-azabicyclo[3.2.1]octane,-   6-(4-isoxazolyl)-3-azabicyclo[3.2.1]octane,-   6-(4-isoxazolyl)-2-azabicyclo[3.3.1]nonane,-   7-(4-isoxazolyl)-2-azabicyclo[3.3.1]nonane,-   8-(4-isoxazolyl)-2-azabicyclo[3.3.1]nonane,-   6-(4-isoxazolyl)-3-azabicyclo[3.3.1]nonane,-   7-(4-isoxazolyl)-3-azabicyclo[3.3.1]nonane,-   4-(4-isoxazolyl)-8-azabicyclo[5.1.1]nonane,-   3-(4-isoxazolyl)-8-azabicyclo[4.3.1]decane,-   8-(4-isoxazolyl)-4-azabicyclo[5.2.1]decane,-   and 9-(4-isoxazolyl)-4-azabicyclo[5.3.1]undecane.

Compounds resulting from substitution of NCH₃ for NH in any of theazabicyclic moieties in the foregoing representative compounds are alsorepresentative compounds of the present invention. In each of thesecompounds, individual stereoisomers thereof, mixtures thereof, includingracemic mixtures, enantiomers, diastereomers, and tautomers thereof, andthe pharmaceutically acceptable salts thereof, are intended to be withinthe scope of the present invention.

II. METHODS OF PREPARING THE COMPOUNDS

As illustrated in Scheme 1, compounds of the present invention arereadily prepared by the Suzuki coupling (Oh-e et al., J. Org. Chem. 58:2201 (1993); Lepifre et al., Tetrahedron Lett. 40(35): 6373 (1999)) ofan appropriate heteroarylboronic acid (or ester) with a N-protectedazabicyclic enol triflate (i.e., trifluoromethanesulfonate) or enolphosphate. The enol triflate or phosphate is, in turn, generated fromthe corresponding azabicyclic ketone, using various methods known tothose skilled in the art of organic synthesis. For instance, treatmentof the ketone with lithium diisopropylamide (LDA) generates thecorresponding enolate, which can be reacted with any of varioustrifluoromethanesulfonating reagents, such asN-phenyltrifluoromethanesulfonimide or2-(N,N-bis(trifluoromethanesulfonyl)amino-5-chloropyridine, to give theenol triflate. Likewise, treatment of the enolate with diphenylchlorophosphate will give the corresponding enol phosphate (Nan andYang, Tetrahedron Lett. 40(17): 3321 (1999)). Alternatively, the ketonecan be treated with trifluoromethanesulfonic anhydride and 2,6-lutidineto generate the enol triflate. Typical Suzuki coupling conditions employpalladium tetrakis(triphenylphosphine), sodium carbonate, and lithiumchloride in a mixture of water and dimethoxyethane. The correspondingnickel catalyzed reaction has been reported for enol phosphatesubstrates (Nan and Yang, Tetrahedron Lett. 40(17): 3321 (1999)). In analternative approach to coupling the heteroaryl group to the azabicycle(also shown in Scheme 1), the N-protected azabicyclic ketone can bereacted with a heteroaryl organometallic reagent (e.g.,3-lithiopyridine) to give a tertiary alcohol. Various methods ofconverting the alcohol into the alkene, either through the intermediacyof a halide derivative or not, can be employed. Such dehydration anddehydrohalogenation reactions are numerous and well known to thoseskilled in the art of organic synthesis.

In yet another approach to coupling the heteroaryl group to theazabicycle, a heteroaryl organometallic reagent (e.g.,3-pyridinyllithium or 3-pyridinylmagnesium bromide) can be reacted withcertain azabicycloalkene precursors, particularly those in which thereis an unsaturated, electron-withdrawing group (CN, —NO₂, —C(═O)NR′R″,—C(═O)R′, —C(═O)OR′, —SO₂R′, —SO₂NR′R″) attached to one of the doublebond carbons. Such systems (known to those skilled in the art as Michaelacceptors) add nucleophilic reagents in a “conjugate” or “1,4” manner,such that the new bond is formed between aryl group and the double bondcarbon which is in the “beta” position to the electron-withdrawinggroup. Such conjugate addition reactions are often catalyzed bytransition metal salts (e.g., cuprous salts). In this case, the productof such a reaction is a compound of Formula 2, in which theelectron-withdrawing group (substituent Z, in the formula) is attachedto the azabicycle at the carbon adjacent to the one bearing theheteroaryl group. Properly chosen electron-withdrawing groups can beused to generate a double bond in conjugation with the heteroaryl group,thus producing a compound of Formula 1.

The protecting groups employed are typically carbamates or amides,either of which may be removed by methods known to those skilled in theart (see Greene and Wuts, Protective Groups in Organic Synthesis 2nded., Wiley-Interscience Pub. (1991). Hydrogenation of the alkene can beperformed before (or after) removal of the protecting group. Thus,compounds of both Formulas 1 and 2 are produced. Further elaboration ofthese materials can be accomplished, for instance by alkylating thesecondary amine to give a tertiary amine. Thus, treatment of thesecondary amine with formic acid and aqueous formaldehyde generates thecorresponding N-methyl derivative. Similarly, treatment of the secondaryamine with benzaldehyde and sodium cyanoborohydride generates theN-benzyl derivative. Various other techniques for accomplishingalkylations are known to those skilled in the art, such that a varietyof alkyl and substituted alkyl groups can be installed at the nitrogenatom of the azabicycle.

The heteroarylboronic acids or esters required for Suzuki coupling areeither commercially available or can be prepared by a number of methodsknown to those skilled in the art of organic synthesis. For instance,halogen-metal exchange of a heteroaromatic halide with an alkyllithium(such as n-butyllithium), and quenching the resulting heteroaryllithiumwith a borate ester produces the heteroarylboronic acid or ester(depending on reaction work-up conditions). Alternatively, aheteroaromatic halide can be treated with pinacolatoborane in thepresence of a palladium catalyst to afford the pinacololboronic ester(Ishiyama et al., J. Org. Chem. 60: 7508 (1995); Murata et al., J. Org.Chem. 65: 164 (2000)).

It will be obvious to those skilled in the art that it may be desirableto obtain the compounds of the present invention in enantiomericallypure form. This can be achieved by introduction of a chiral auxiliaryinto the substrate. For example, derivatization of the secondarynitrogen, of a racemic compound of the Formula 1 or 2, with anenantiomerically pure carbamate or amide protecting group will generatea pair of diastereomeric compounds. The separation of thesediastereomeric intermediates is typically achieved by crystallization orchromatography, affording the pure enantiomers when the chiral auxiliaryis removed at a later stage.

Specific Ring Systems

The compounds according to Formulas 1 and 2, wherein k=n=0 and m=p=1,and the isomeric compounds according to Formulas 1 and 2, wherein k=m=1and n=p=0, possess the 6-azabicyclo[3.2.1]octane core and are preparedfrom the same azabicyclic ketone intermediate,6-azabicyclo[3.2.1]octan-3-one. Syntheses of various N-protectedderivatives of this ketone have been reported (Carroll et al., J. Chem.Soc. Perkin Trans. I, 1375 (1991); Trost and Genet, J. Am. Chem. Soc.98: 8516 (1976); Gensler et al., J. Org. Chem. 33: 2968 (1968); Furstosset al., J. Chem. Soc. Chem. Comm. 30: 805 (1970); Winkler et al., J. Am.Chem. Soc. 123: 7429 (2001); Asaoka et al., Heterocycles 38: 2455(1994); and Huffman et al., J. Org. Chem. 32: 697 (1967)). Mostconveniently, the procedure of Carroll is employed (Scheme 2). Thus,iodolactonization of 3-cyclohexenecarboxylic acid and subsequentbase-induced elimination gives the unsaturated lactone. Opening of thelactone with benzylamine affords the amide, which is reduced to theamino alcohol with lithium aluminum hydride. Oxidation of the allylicalcohol functionality with manganese dioxide gives directly the bicyclicproduct of an intramolecular Michael addition. It was found to beadvantageous to exchange the benzyl protecting group for a carbamate,for example, t-butyl carbamate. This is accomplished by chloroformatedealkylation and subsequent reaction of the secondary amine withdi-t-butyl dicarbonate. Thus prepared, theN-(t-butoxycarbonyl)-6-azabicyclo[3.2.1]octan-3-one is converted bypreviously described methods (enol triflate formation and Suzukicoupling) into compounds of the present invention. In this case, twoisomeric enol triflates (and therefore, two isomeric Suzuki products)are formed, representing the two positional isomers of the double bondwith respect to the nitrogen containing bridge. These are separablechromatographically.

The compounds according to Formulas 1 and 2, wherein k=m=0 and n=p=1,also possess the 6-azabicyclo[3.2.1]octane core, but are isomeric withthe previous examples by virtue of the attachment between the azabicycleand the heteroaryl group. The ketone intermediate, N-protected6-azabicyclo[3.2.1]octan-4-one, is prepared from thehydroxycyclohexenecarboxamide intermediate described in Scheme 2. Thus,as shown in Scheme 3, treatment of this intermediate with thionylchloride or methanesulfonyl chloride converts the allylic alcohol intothe allylic chloride or mesylate. Intramolecular alkylation is thenachieved by treatment with a base (such as potassium t-butoxide),providing the desired 7-oxo-6-azabicyclo[3.2.1]oct-3-ene. Conversion ofthe alkene to the epoxide, followed by reduction of both the lactam andepoxide functionalities with lithium aluminum hydride providesN-benzyl-6-azabicyclo[3.2.1]octan-4-ol. Removal of the benzylicprotecting group by hydrogenation with palladium on charcoal in thepresence of di-t-butyl dicarbonate gave the t-butyl carbamate. Oxidationof the hydroxyl group is accomplished by either a chromium (VI) basedoxidant or Swern conditions, to give the corresponding6-azabicyclo[3.2.1]octan-4-one. This ketone is transformed, by methodspreviously described, into compounds of Formulas 1 and 2. For methods ofproducing other similar 6-azabicyclo[3.2.1]octane intermediates, usefulin the synthesis of compounds of the present invention, see Weinreb etal., Tet. Lett. 41: 2333 (2000); Mazzocchi et al., J. Org. Chem. 46:4530 (1981); Krow et al., Syn. Comm. 13: 575 (1983); Kuehne and Horne,J. Org. Chem. 40: 1287 (1974); and Waegell et al., J. Org. Chem. 43:3746 (1978).

Compounds according to Formulas 1 and 2, wherein k=m=p=1 and n=0,possess the 3-azabicyclo[3.3.1]nonane core. The ketone intermediate,N-protected 3-azabicyclo[3.3.1]nonan-7-one, is known (Bok and Speckamp,Tetrahedron 35: 267 (1979)) and is conveniently prepared using thesequence illustrated in Scheme 4. Birch reduction of5-methoxyisophthalic acid or 5-aminoisophthalic acid, followed by acidichydrolysis of the resulting intermediates gives the saturatedcyclohexanone-3,5-cis-dicarboxylic acid. Esterification and protectionof the ketone carbonyl as the ketal is followed by reduction to thediol. Mesylation, and treatment with ammonium hydroxide, results information of the bicyclic amine. Protection of the secondary amine asthe ethyl carbamate and acidic deprotection of the ketal gives thedesired ketone. This is converted into compounds of the presentinvention using methods already described.

Preparation of compounds according to Formula 1 and 2, wherein k=p=1 andm=n=0, possess the 3-azabicyclo[3.2.1]octane core, and the synthesis ofa ketone intermediate, 3-azabicyclo[3.2.1]octan-6-one, is shown inScheme 5. Thus, Diels-Alder reaction of 2-chloroacrylonitrile andcyclopentadiene affords an adduct, which is then hydrolyzed under basicconditions and subjected to steam distillation to give thebicyclo[2.2.1]hept-5-en-2-one (Freeman et al., J. Org. Chem. 33: 2211(1968); Greene et al., J. Am. Chem. Soc. 104: 5473 (1982)). Protectionof the carbonyl group as the ketal, followed by ozonolytic cleavage andimmediate reduction of the resulting dialdehyde gives the diol.Conversion of the diol into the bis-mesylate, followed by displacementwith ammonia, then produces the desired azabicycle. Protection of thenitrogen as the ethyl carbamate and acidic cleavage of the ketal gives3-azabicyclo[3.2.1]octan-6-one. This is converted into compounds of thepresent invention using methods already described.

A variety of other azabicyclic ketones can be intermediates for thesynthesis of compounds of the present invention. One example of such aketone is 3-azabicyclo[3.3.1]nonan-6-one, which can be made according toone of the following literature methods: Oppolzer, Tetrahedron 41(17):3447 (1985); Speckamp et al., Heterocycles 12(3): 343 (1979); Johnson etal., J. Org. Chem. 33: 3195 (1968) or Johnson et al., J. Org. Chem. 34:3834 (1969). Another example of such a ketone is6-azabicyclo[3.2.1]octan-2-one, which can be prepared according to themethod of Bonjoch et al., Tetrahedron: Asymmetry 10(12): 2399 (1999).Another example is 2-azabicyclo[3.2.1]octan-7-one, which can be made bythe method of Ikeda et al., Heterocycles 54(2): 747 (2001). Anotherexample is 2-azabicyclo[3.3.1]nonan-6-one, which can be made by themethod of Boger et al., Tet. Lett. 23(44): 4559 (1982).

III. PHARMACEUTICAL COMPOSITIONS

The compounds described herein can be incorporated into pharmaceuticalcompositions and used to prevent a condition or disorder in a subjectsusceptible to such a condition or disorder, and/or to treat a subjectsuffering from the condition or disorder. The pharmaceuticalcompositions described herein include one or more compounds of Formulas1 or 2 and/or pharmaceutically acceptable salts thereof. Chiralcompounds can be employed as racemic mixtures or as pure enantiomers.

In one embodiment, the compounds described herein can be incorporatedinto pharmaceutical compositions and used to bring about smokingcessation, treat drug addiction, or treat or prevent obesity. In thisembodiment, upon administration, the active ingredients interact withreceptor sites within the body of the subject that control dopaminerelease.

In this embodiment, the ability of compounds to partially inhibit therelease of dopamine is especially significant, as it indicates that thecompounds can be useful in interrupting the dopamine reward system, andthus in treating disorders that are mediated by it. Such disordersinclude substance abuse, tobacco use and weight gain.

Thus, in this embodiment, the compounds are a useful alternative intreating dependencies on drugs of abuse including alcohol, amphetamines,barbiturates, benzodiazepines, caffeine, cannabinoids, cocaine,hallucinogens, opiates, phencyclidine and tobacco and the treatment ofeating disorders, such as obesity that occurs following drug cessation,while reducing side effects associated with the use of psychomotorstimulants (agitation, sleeplessness, addiction, etc.).

In this embodiment, the compounds also advantageously affect thefunctioning of the CNS, in a manner which is designed to optimize theeffect upon those relevant receptor subtypes that have an effect upondopamine release, while minimizing the effects upon muscle-type receptorsubtypes.

In certain circumstances, the compounds can be used as part of apharmaceutical composition with other compounds intended to prevent ortreat drug addiction, nicotine addiction, and/or obesity. In addition toeffective amounts of the compounds described herein, the pharmaceuticalcompositions can also include various other components as additives oradjuncts. Exemplary pharmaceutically acceptable components or adjunctswhich are employed in relevant circumstances include antidepressants,antioxidants, free-radical scavenging agents, peptides, growth factors,antibiotics, bacteriostatic agents, immunosuppressives, anticoagulants,buffering agents, anti-inflammatory agents, anti-pyretics, time-releasebinders, anaesthetics, steroids, vitamins, minerals and corticosteroids.Such components can provide additional therapeutic benefit, act toaffect the therapeutic action of the pharmaceutical composition, or acttowards preventing any potential side effects which can be imposed as aresult of administration of the pharmaceutical composition.

The manner in which the compounds are administered can vary. Thecompositions are preferably administered orally (e.g., in liquid formwithin a solvent such as an aqueous or non-aqueous liquid, or within asolid carrier). Preferred compositions for oral administration includepills, tablets, capsules, caplets, syrups, and solutions, including hardgelatin capsules and time-release capsules. Compositions can beformulated in unit dose form, or in multiple or subunit doses. Preferredcompositions are in liquid or semisolid form. Compositions including aliquid pharmaceutically inert carrier such as water or otherpharmaceutically compatible liquids or semisolids can be used. The useof such liquids and semisolids is well known to those of skill in theart.

The compositions can also be administered via injection, i.e.,intravenously, intramuscularly, subcutaneously, intraperitoneally,intraarterially, intrathecally; and intracerebroventricularly.Intravenous administration is the preferred method of injection.Suitable carriers for injection are well known to those of skill in theart and include 5% dextrose solutions, saline, and phosphate-bufferedsaline. The compounds can also be administered as an infusion orinjection (e.g., as a suspension or as an emulsion in a pharmaceuticallyacceptable liquid or mixture of liquids).

The formulations can also be administered using other means, forexample, rectal administration. Formulations useful for rectaladministration, such as suppositories, are well known to those of skillin the art. The compounds can also be administered by inhalation (e.g.,in the form of an aerosol either nasally or using delivery articles ofthe type set forth in U.S. Pat. No. 4,922,901 to Brooks et al., thedisclosure of which is incorporated herein in its entirety); topically(e.g., in lotion form); or transdermally (e.g., using a transdermalpatch, using technology that is commercially available from Novartis andAlza Corporation). Although it is possible to administer the compoundsin the form of a bulk active chemical, it is preferred to present eachcompound in the form of a pharmaceutical composition or formulation forefficient and effective administration.

Exemplary methods for administering such compounds will be apparent tothe skilled artisan. The usefulness of these formulations can depend onthe particular composition used and the particular subject receiving thetreatment. These formulations can contain a liquid carrier that can beoily, aqueous, emulsified or contain certain solvents suitable to themode of administration.

The compositions can be administered intermittently or at a gradual,continuous, constant or controlled rate to a warm-blooded animal (e.g.,a mammal such as a mouse, rat, cat, rabbit, dog, pig, cow, or monkey),but advantageously are administered to a human being. In addition, thetime of day and the number of times per day that the pharmaceuticalformulation is administered can vary.

Preferably, upon administration, the active ingredients interact withreceptor sites within the body of the subject that affect thefunctioning of the CNS. More specifically, in treating a CNS disorder,preferable administration is designed to optimize the effect upon thoserelevant nicotinic acethylcholine receptor (nAChR) subtypes that have aneffect upon the functioning of the CNS, while minimizing the effectsupon muscle-type receptor subtypes. Other suitable methods foradministering the compounds of the present invention are described inU.S. Pat. No. 5,604,231 to Smith et al., the contents of which arehereby incorporated by reference.

In certain circumstances, the compounds described herein can be employedas part of a pharmaceutical composition with other compounds intended toprevent or treat a particular disorder. In addition to effective amountsof the compounds described herein, the pharmaceutical compositions canalso include various other components as additives or adjuncts.Exemplary pharmaceutically acceptable components or adjuncts which areemployed in relevant circumstances include antioxidants, free-radicalscavenging agents, peptides, growth factors, antibiotics, bacteriostaticagents, immunosuppressives, anticoagulants, buffering agents,anti-inflammatory agents, anti-pyretics, time-release binders,anesthetics, steroids, vitamins, minerals, and corticosteroids. Suchcomponents can provide additional therapeutic benefit, act to affect thetherapeutic action of the pharmaceutical composition, or act towardspreventing any potential side effects that can be imposed as a result ofadministration of the pharmaceutical composition.

The appropriate dose of the compound is that amount effective to preventoccurrence of the symptoms of the disorder or to treat some symptoms ofthe disorder from which the patient suffers. By “effective amount”,“therapeutic amount” or “effective dose” is meant that amount sufficientto elicit the desired pharmacological or therapeutic effects, thusresulting in effective prevention or treatment of the disorder.

When treating a CNS disorder, an effective amount of compound is anamount sufficient to pass across the blood-brain barrier of the subject,to bind to relevant receptor sites in the brain of the subject and tomodulate the activity of relevant nAChR subtypes (e.g., provideneurotransmitter secretion, thus resulting in effective prevention ortreatment of the disorder). Prevention of the disorder is manifested bydelaying the onset of the symptoms of the disorder. Treatment of thedisorder is manifested by a decrease in the symptoms associated with thedisorder or an amelioration of the recurrence of the symptoms of thedisorder. Preferably, the effective amount is sufficient to obtain thedesired result, but insufficient to cause appreciable side effects.

The effective dose can vary, depending upon factors such as thecondition of the patient, the severity of the symptoms of the disorder,and the manner in which the pharmaceutical composition is administered.For human patients, the effective dose of typical compounds generallyrequires administering the compound in an amount sufficient to modulatethe activity of relevant CNS nAChRs (e.g., to effect neurotransmitterrelease), but the amount should be insufficient to induce effects onskeletal muscles and ganglia to any significant degree. The effectivedose of compounds will of course differ from patient to patient, but ingeneral includes amounts starting where CNS effects or other desiredtherapeutic effects occur but below the amount where muscular effectsare observed.

For use in treating drug addiction, nicotine addiction and/or obesity,the effective dose of typical compounds generally requires administeringthe compound in an amount sufficient to decrease dopamine release, butthe amount should be insufficient to induce effects on skeletal musclesand ganglia to any significant degree. A particular dose of compoundeffective in preventing and/or treating drug addiction, nicotineaddiction and/or obesity (primarily but not necessarily the obesityassociated drug or nicotine cessation) is essentially ineffective ineliciting activation of certain ganglionic-type nicotinic receptors atconcentration higher than 5 times, preferably higher than 100 times, andmore preferably higher than 1,000 times than those required forsuppression of dopamine production and/or release. This selectivity ofcertain compounds described herein against those ganglionic-typereceptors responsible for cardiovascular side effects is demonstrated bya lack of the ability of those compounds to activate nicotinic functionof adrenal chromaffin tissue at concentrations greater than thoserequired for suppression of dopamine production and/or release.

The compounds, when employed in effective amounts in accordance with themethod described herein, are selective to certain relevant nAChRs, butdo not interact significantly with receptors associated with undesirableside effects at concentrations at least greater than those required formodulating the release of dopamine or other neurotransmitters. By thisis meant, for instance, that a particular dose of compound effective inpreventing and/or treating a CNS disorder is substantially ineffectivein eliciting activation of certain ganglionic-type nAChRs atconcentration higher than 5 times, preferably higher than 100 times, andmore preferably higher than 1,000 times than those required formodulation of neurotransmitter release. This selectivity of certaincompounds described herein against those ganglionic-type receptorsresponsible for cardiovascular side effects is demonstrated by a lack ofthe ability of those compounds to activate nicotinic function of adrenalchromaffin tissue at concentrations greater than those required formodulation of dopamine release.

The compounds described herein, when employed in effective amounts inaccordance with the methods described herein, can provide some degree ofprevention of the progression of CNS disorders, ameliorate symptoms ofCNS disorders, and ameliorate to some degree of the recurrence of CNSdisorders. The effective amounts of those compounds are typically belowthe threshold concentration required to elicit any appreciable sideeffects, for example those effects relating to skeletal muscle. Thecompounds can be administered in a therapeutic window in which certainCNS disorders are treated and certain side effects are avoided. Ideally,the effective dose of the compounds described herein is sufficient toprovide the desired effects upon the CNS but is insufficient (i.e., isnot at a high enough level) to provide undesirable side effects.Preferably, the compounds are administered at a dosage effective fortreating the CNS disorders but less than ⅕, and often less than 1/10,the amount required to elicit certain side effects to any significantdegree.

Most preferably, effective doses are at very low concentrations, wheremaximal effects are observed to occur, with a minimum of side effects.Typically, the effective dose of such compounds generally requiresadministering the compound in an amount of less than 5 mg/kg of patientweight. Often, the compounds of the present invention are administeredin an amount from less than about 1 mg/kg patent weight and usually lessthan about 100 μg/kg of patient weight, but frequently between about 10μg to less than 100 μg/kg of patient weight. For compounds that do notinduce effects on muscle-type nicotinic receptors at low concentrations,the effective dose is less than 5 mg/kg of patient weight; and oftensuch compounds are administered in an amount from 50 μg to less than 5mg/kg of patient weight. The foregoing effective doses typicallyrepresent that amount administered as a single dose, or as one or moredoses administered over a 24-hour period.

For human patients, the effective dose of typical compounds generallyrequires administering the compound in an amount of at least about 1,often at least about 10, and frequently at least about 25 μg/24hr/patient. For human patients, the effective dose of typical compoundsrequires administering the compound which generally does not exceedabout 500, often does not exceed about 400, and frequently does notexceed about 300 μg/24 hr/patient. In addition, the compositions areadvantageously administered at an effective dose such that theconcentration of the compound within the plasma of the patient normallydoes not exceed 500 pg/ml, often does not exceed 300 pg/ml, andfrequently does not exceed 100 pg/ml.

IV. METHODS OF USING THE COMPOUNDS AND/OR PHARMACEUTICAL COMPOSITIONS

The compounds can be used to treat those types of conditions anddisorders for which other types of nicotinic compounds have beenproposed as therapeutics. See, for example, Williams et al., Drug NewsPerspec. 7(4):205 (1994), Arneric et al., CNS Drug Rev. 1(1):1 (1995),Arneric et al., Exp. Opin. Invest. Drugs 5(1):79 (1996), Bencherif etal., J. Pharmacol. Exp. Ther. 279:1413 (1996), Lippiello et al., J.Pharmacol. Exp. Ther. 279:1422 (1996), Damaj et al., J. Pharmacol. Exp.Ther. 291:390 (1999); Chiari et al., Anesthesiology 91:1447 (1999);Lavand'homme and Eisenbach, Anesthesiology 91:1455 (1999); Neuroscience(1997), Holladay et al., J. Med. Chem. 40(28):4169 (1997), Bannon etal., Science 279:77 (1998), PCT WO 94/08992, PCT WO 96/31475, and U.S.Pat. Nos. 5,583,140 to Bencherif et al., 5,597,919 to Dull et al., and5,604,231 to Smith et al., the disclosures of each of which areincorporated herein by reference in their entirety.

More particularly, the certain compounds can be used to treat thosetypes of conditions and disorders for which nicotinic compounds withselectivity for the α7 nAChR subtype have been proposed as therapeutics.See, for example, Leonard et al., Schizophrenia Bulletin 22(3): 431(1996), Freedman et al., Biol. Psychiatry 38(1): 22 (1995), Heeschen etal., J. Clin. Invest. 100: 527 (2002), Utsugisawa et al., MolecularBrain Research 106(1-2): 88 (2002), U.S. Patent Application2002/0016371, Levin and Rezvani, Current Drug Targets: CNS andNeurological Disorders 1(4): 423 (2002)), O'Neill et al., Current DrugTargets: CNS and Neurological Disorders 1(4): 399 (2002, Jeyarasasingamet al., Neuroscience 109(2): 275 (2002)), Xiao et al., Proc. Nat. Acad.Sci. (US) 99(12): 8360 (2002)), PCT WO 99/62505, PCT WO 99/03859, PCT WO97/30998, PCT WO 01/36417, PCT WO 02/15662, PCT WO 02/16355, PCT WO02/16356, PCT WO 02/16357, PCT WO 02/16358, PCT WO 02/17358, Stevens etal., Psychopharm. 136: 320 (1998), Dolle et al., J. Labelled Comp.Radiopharm. 44: 785 (2001) and Macor et al., Bioorg. Med. Chem. Lett.11: 319 (2001) and references therein, the contents of each of which arehereby incorporated by reference in their entirety.

The compounds can also be used as adjunct therapy in combination withexisting therapies in the management of the aforementioned types ofdiseases and disorders. In such situations, it is preferably toadminister the active ingredients in a manner that minimizes effectsupon nAChR subtypes such as those that are associated with muscle andganglia. This can be accomplished by targeted drug delivery and/or byadjusting the dosage such that a desired effect is obtained withoutmeeting the threshold dosage required to achieve significant sideeffects. The pharmaceutical compositions can be used to ameliorate anyof the symptoms associated with those conditions, diseases, anddisorders. Representative classes of disorders that can be treated arediscussed in detail below.

Treatment of CNS Disorders

Examples of conditions and disorders that can be treated includeneurological disorders and neurodegenerative disorders, and, inparticular, CNS disorders. CNS disorders can be drug induced; can beattributed to genetic predisposition, infection or trauma; or can be ofunknown etiology. CNS disorders comprise neuropsychiatric disorders,neurological diseases, and mental illnesses, and includeneurodegenerative diseases, behavioral disorders, cognitive disorders,and cognitive affective disorders. There are several CNS disorders whoseclinical manifestations have been attributed to CNS dysfunction (i.e.,disorders resulting from inappropriate levels of neurotransmitterrelease, inappropriate properties of neurotransmitter receptors, and/orinappropriate interaction between neurotransmitters and neurotransmitterreceptors). Several CNS disorders can be attributed to a deficiency ofcholine, dopamine, norepinephrine and/or serotonin.

Examples of CNS disorders that can be treated in accordance with thepresent invention include pre-senile dementia (early onset Alzheimer'sdisease), senile dementia (dementia of the Alzheimer's type), Lewy Bodydementia, micro-infarct dementia, AIDS-related dementia, HIV-dementia,multiple cerebral infarcts, Parkinsonism including Parkinson's disease,Pick's disease, progressive supranuclear palsy, Huntington's chorea,tardive dyskinesia, hyperkinesia, mania, attention deficit disorder,anxiety, depression, dyslexia, schizophrenia, obsessive-compulsivedisorders, Tourette's syndrome, mild cognitive impairment (MCI),age-associated memory impairment (AAMI), premature amnesic, andcognitive disorders which are age-related or a consequence ofalcoholism, or immunodeficiency syndrome, or are associated withvascular disorders, with genetic alterations (such as, for example,trisomy 21) or with attention deficiencies or learning deficiencies,acute or chronic neurodegenerative conditions such as amyotrophiclateral sclerosis, multiple sclerosis, peripheral neurotrophies, andcerebral or spinal traumas. In addition, the compounds can be used totreat nicotine addiction and/or other behavioral disorders related tosubstances that lead to dependency (e.g., alcohol, cocaine, heroin andother opiates, psychostimulants, benzodiazepines, and barbiturates).Schizophrenia is an example of a CNS disorder that is particularlyamenable to treatment by modulating the α7 nAChR subtype. The compoundscan also be administered to improve cognition and/or provideneuroprotection, and these uses are also particularly amenable totreatment with compounds, such as those compounds of the presentinvention that are specific for the α7 nAChR subtype.

Schizophrenic patients suffer from positive symptoms (hallucination) andnegative symptoms (depression and cognitive deficiency). With respect totreatment of schizophrenia, modulation of the α7 receptor tends to bemore important than modulation of the α4β2 receptor with respect totreating hallucination. However, modulation of the α4β2 receptor isuseful for treating the negative symptoms associated schizophrenia (aswell as those aggravated with conventional anti-schizophreniacompounds), such as mood alteration, attention deficit and cognitivedeficiency.

Those compounds that bind to both receptors (or mixtures of compounds,where one binds to the α7 receptor and another binds to the α4β2receptor) can be used to not only treat the positive and negativesymptoms of schizophrenia, but also common side effects associated withconventional anti-schizophrenia treatments. The compounds can alsoprovide a neuroprotective effect to these patients.

The disorders can be treated and/or prevented by administering to apatient in need of treatment or prevention thereof an effectivetreatment or preventative amount of a compound that provides some degreeof prevention of the progression of a CNS disorder (i.e., providesprotective effects), ameliorating the symptoms of the disorder, andameliorating the recurrence of the disorder.

Anti-Inflammatory Uses

Excessive inflammation and tumor necrosis factor synthesis causemorbidity and even mortality in a variety of diseases. These diseasesinclude, but are not limited to, endotoxemia, sepsis, rheumatoidarthritis, and irritable bowel disease. The nervous system, primarilythrough the vagus nerve, is known to regulate the magnitude of theinnate immune response by inhibiting the release of macrophage tumornecrosis factor (TNF). This physiological mechanism is known as the“cholinergic anti-inflammatory pathway” (see, for example, Tracey,Nature 420: 853 (2002)).

The nicotinic acetylcholine receptor α7 subunit is required foracetylcholine inhibition of macrophage TNF release, and also inhibitsrelease of other cytokines. Agonists (or, at elevated dosages, partialagonists) at the α7-specific receptor subtype can inhibit theTNF-modulated inflammatory response. Accordingly, those compoundsdescribed herein that are α7 agonists can be used to treat inflammatorydisorders characterized by excessive synthesis of TNF (see also Wang etal., Nature 421: 384 (2003)).

Inflammatory conditions that can be treated or prevented byadministering the compounds described herein include, but are notlimited to, chronic and acute inflammation, psoriasis, gout, acutepseudogout, acute gouty arthritis, arthritis, rheumatoid arthritis,osteoarthritis, allograft rejection, chronic transplant rejection,asthma, atherosclerosis, mononuclear-phagocyte dependent lung injury,idiopathic pulmonary fibrosis, atopic dermatitis, chronic obstructivepulmonary disease, adult respiratory distress syndrome, acute chestsyndrome in sickle cell disease, inflammatory bowel disease, Crohn'sdisease, ulcerative colitis, acute cholangitis, aphteous stomatitis,glomerulonephritis, lupus nephritis, thrombosis, and graft vs. hostreaction. Fibromyalgia syndrome can also be treated with agonists of theα7 receptor.

Minimizing the Inflammatory Response Associated with Bacterial and/orViral Infection Many bacterial and/or viral infections are associatedwith side effects brought on by the formation of toxins, and the body'snatural response to the bacteria or virus and/or the toxins. Examples ofsuch bacterial infections include anthrax, botulism, and sepsis. Asdiscussed above, the body's response to infection often involvesgenerating a significant amount of TNF and/or other cytokines. Theover-expression of these cytokines can result in significant injury,such as septic shock, endotoxic shock, urosepsis, and toxic shocksyndrome.

Cytokine expression is mediated by the α7 nAChR, and can be inhibited byadministering agonists or partial agonists of these receptors. Thosecompounds described herein that are agonists or partial agonists ofthese receptors can therefore be used to minimize the inflammatoryresponse associated with bacterial infection, as well as viral andfungal infections. Certain of the compounds themselves can also haveantimicrobial properties.

These compounds can also be used as adjunct therapy in combination withexisting therapies to manage bacterial, viral and fungal infections,such as antibiotics, antivirals and antifungals. Antitoxins can also beused to bind to toxins produced by the infectious agents and allow thebound toxins to pass through the body without generating an inflammatoryresponse. Examples of antitoxins are disclosed, for example, in U.S.Pat. No. 6,310,043 to Bundle et al., incorporated herein by reference.Other agents effective against bacterial and other toxins can beeffective and their therapeutic effect can be complimented byco-administration with the compounds described herein.

Analgesic Uses

The compounds can be administered to treat and/or prevent pain,including neurologic, neuropathic and chronic pain. The analgesicactivity of compounds described herein can be demonstrated in models ofpersistent inflammatory pain and of neuropathic pain, performed asdescribed in U.S. Published Patent Application No. 20010056084 A1 toAllgeier et al. (e.g., mechanical hyperalgesia in the complete Freund'sadjuvant rat model of inflammatory pain and mechanical hyperalgesia inthe mouse partial sciatic nerve ligation model of neuropathic pain). Theanalgesic effect is suitable for treating pain of various genesis oretiology, in particular in treating inflammatory pain and associatedhyperalgesia, neuropathic pain, and associated hyperalgesia, chronicpain (e.g., severe chronic pain, post-operative pain, and painassociated with various conditions including cancer, angina, renal orbilliary colic, menstruation, migraine, and gout). Inflammatory pain canbe of diverse genesis, including arthritis and rheumatoid disease,teno-synovitis, and vasculitis. Neuropathic pain includes trigeminal orherpetic neuralgia, diabetic neuropathy pain, causalgia, low back pain,and deafferentation syndromes such as brachial plexus avulsion.

An additional class of pains particularly suited to treatment with thepresent compounds are injury-related or “nociceptive” pains.Nicotine-induced antinociception appears to be a complex phenomenon thatinvolves multiple nicotinic receptor subtypes depending on the pain typeand sites of action. Based on available pharmacological data, however,it is evident that neuronal nAChRs are engaged; specifically, α4β2neuronal subtypes have been implicated in thermal acute pain tests suchas hot-plate (and tail-flick assays (which involves a spinal reflex).The α7 nAChR is also associated with modulating pain transmission in theCNS in a variety of species and pain tests, as shown by studiessuggesting that activation of α7 receptors in the CNS elicitsantinociceptive effects in an acute thermal pain model. See, forinstance, Damaj, M. I., et al., The antinociceptive effects of α7nicotinic agonists in an acute pain model. Neuropharmacology39:2785-2791 (2000) (the disclosure of which is hereby incorporatedherein by reference in its entirety), and references cited therein,which provide guidance regarding appropriate animal models forevaluating the compounds described herein, including an acute thermalpain model in mice.

Additional animal models for evaluating antinociceptive activities ofthe compounds herein or antinociceptive activity and behavioral effectscharacteristic of nicotinic ligands with selectivity for neuronal nAChRsare described, for instance, in Bannon, A. W., et al., ABT-594[(R)-5-(2-azetidinylmethoxy)-2-chloropyridine]: a novel, orallyeffective antinociceptive agent acting via neuronal nicotinicacetylcholine receptors: II. In vivo characterization. J. Pharmaco. IExp. Ther. 285:787-794 (1998) (the disclosure of which is herebyincorporated herein by reference in its entirety), including: a ratmodel of acute thermal (hot box) and persistent chemical (formalin test)pain; a rodent model for effects on motor function (to differentiatemotor function from analgesic effects) and electroencephalogram (EEG; todetect morphine-like sedating side effects), and the use of opioidreceptor antagonists and nAChR antagonists, such as mecamylamine, toshow nAChR specificity. Further relevant animal models are described,for instance, in Damaj. M. I., et al., Antinociceptive andpharmacological effects of metanicotine, a selective nicotinic agonist.J. Pharmacol. Exp. Ther. 291:390-398 (1999) (the disclosure of which ishereby incorporated herein by reference in its entirety), including thefollowing: rodent models for antinociceptive activity and behavioraleffects of nicotinic ligands with selectivity for neuronal nAChRs: acutethermal (mouse tail-flick and hot-plate tests), mechanical (paw-pressuretest in rats), and visceral [paraphenylquinone (PPQ)] pain tests;persistent and chronic pain (mouse formalin test and arthritic painmodel, respectively); behavioral models (locomotor activity, drugdiscrimination, and body temperature measurement), for ascertainingnicotinic effects and evaluating a compound as a potential analgesicdrug with fewer side effects than those presently available.

While not wishing to be bound to a particular theory, it is believedthat some analgesia is associated with the α4β2 receptor, and someanalgesia is associated with the α7 receptor. Accordingly, thosecompounds that bind to both receptors (or a combination of compoundsthat bind to both receptors) can offer a wider spectrum of analgesiathan compounds that only bind to one of these receptors.

Inhibition of Neovascularization

The α7 nAChR is also associated with neovascularization. Inhibition ofneovascularization, for example, by administering antagonists (or atcertain dosages, partial agonists) of the α7 nAChR can treat or preventconditions characterized by undesirable neovascularization orangiogenesis. Such conditions can include those characterized byinflammatory angiogenesis and/or ischemia-induced angiogenesis.Neovascularization associated with tumor growth can also be inhibited byadministering those compounds described herein that function asantagonists or partial agonists of α7 nAChR.

Specific antagonism of α7 nAChR-specific activity reduces the angiogenicresponse to inflammation, ischemia, and neoplasia. Guidance regardingappropriate animal model systems for evaluating the compounds describedherein can be found, for example, in Heeschen et al., J. Clin. Invest.110(4): 527 (2002), incorporated herein by reference regardingdisclosure of α7-specific inhibition of angiogenesis and cellular (invitro) and animal modeling of angiogenic activity relevant to humandisease, especially the Lewis lung tumor model (in vivo, in mice—see, inparticular, pages 529, and 532-533).

Representative tumor types that can be treated using the compoundsdescribed herein include non-small cell lung cancer (NSCLC), ovariancancer, pancreatic cancer, breast carcinoma, colon carcinoma, rectumcarcinoma, lung carcinoma, oropharynx carcinoma, hypopharynx carcinoma,esophagus carcinoma, stomach carcinoma, pancreas carcinoma, livercarcinoma, gallbladder carcinoma, bile duct carcinoma, small intestinecarcinoma, urinary tract carcinoma, kidney carcinoma, bladder carcinoma,urothelium carcinoma, female genital tract carcinoma, cervix carcinoma,uterus carcinoma, ovarian carcinoma, choriocarcinoma, gestationaltrophoblastic disease, male genital tract carcinoma, prostate carcinoma,seminal vesicles carcinoma, testes carcinoma, germ cell tumors,endocrine gland carcinoma, thyroid carcinoma, adrenal carcinoma,pituitary gland carcinoma, skin carcinoma, hemangiomas, melanomas,sarcomas, bone and soft tissue sarcoma, Kaposi's sarcoma, tumors of thebrain, tumors of the nerves, tumors of the eyes, tumors of the meninges,astrocytomas, gliomas, glioblastomas, retinoblastomas, neuromas,neuroblastomas, Schwannomas, meningiomas, solid tumors arising fromhematopoietic malignancies (such as leukemias, chloromas, plasmacytomas,and the plaques and tumors of mycosis fungoides and cutaneous T-celllymphoma/leukemia), and solid tumors arising from lymphomas.

The compounds can also be administered in conjunction with other formsof anti-cancer treatment, including co-administration withantineoplastic antitumor agents such as cis-platin, adriamycin,daunomycin, and the like, and/or anti-VEGF (vascular endothelial growthfactor) agents, as such are known in the art.

The compounds can be administered in such a manner that they aretargeted to the tumor site. For example, the compounds can beadministered in microspheres, microparticles or liposomes conjugated tovarious antibodies that direct the microparticles to the tumor.Additionally, the compounds can be present in microspheres,microparticles or liposomes that are appropriately sized to pass throughthe arteries and veins, but lodge in capillary beds surrounding tumorsand administer the compounds locally to the tumor. Such drug deliverydevices are known in the art.

Treatment of Drug Addiction, Nicotine Addiction and/or Obesity

The compounds can be used to treat drug addiction, nicotine addictionand/or obesity, such as the obesity associated with drug cessation. Thecompounds can also be used as adjunct therapy in combination withexisting therapies in the management of the aforementioned types ofdiseases and disorders. In such situations, it is preferable toadminister the active ingredients to in a manner that optimizes effectsupon dopamine production and/or secretion, while minimizing effects uponreceptor subtypes such as those that are associated with muscle andganglia. This can be accomplished by targeted drug delivery and/or byadjusting the dosage such that a desired effect is obtained withoutmeeting the threshold dosage required to achieve significant sideeffects.

In this embodiment, the compounds have the ability to bind to, and inmost circumstances, antagonize or partially antagonize one or morenicotinic receptors of the brain of the patient that modulate dopaminerelease, other than the α4β2 receptor, at concentrations at which theα4β2 receptor is largely unaffected. As such, such compounds have theability to express nicotinic pharmacology, and in particular, to act asdopamine antagonists.

Accordingly, in this embodiment, the compounds are effective atsuppressing of dopamine production and/or release, and can be used totreat drug addiction, nicotine addiction, and/or obesity at effective atconcentrations that are not sufficient to elicit any appreciable sideeffects, as is demonstrated by decreased effects on preparationsbelieved to reflect effects on the cardiovascular system, or effects toskeletal muscle. As such, administration of the compounds provides atherapeutic window in which treatment of drug addiction, nicotineaddiction and/or obesity is effected, and side effects are avoided. Thatis, an effective dose of a compound of the present invention issufficient to provide the desired antagonistic effects on dopamineproduction and/or secretion, but is insufficient (i.e., is not at a highenough level) to provide undesirable side effects. Preferably, thecompounds results in treatment of drug addiction, nicotine addictionand/or obesity upon administration of less ⅓, frequently less than ⅕,and often less than 1/10, that amount sufficient to cause any sideeffects to a significant degree.

Other Disorders

In addition to treating CNS disorders, inflammatory disorders, andneovascular disorders, and inhibiting the pain response, the compoundscan be also used to prevent or treat certain other conditions, diseases,and disorders. Examples include autoimmune disorders such as Lupus,disorders associated with cytokine release, cachexia secondary toinfection (e.g., as occurs in AIDS, AIDS related complex and neoplasia),as well as those indications set forth in PCT WO 98/25619. The compoundscan also be administered to treat convulsions such as those that aresymptomatic of epilepsy, and to treat conditions such as syphilis andCreutzfeld-Jakob disease.

Diagnostic Uses

The compounds can be used in diagnostic compositions, such as probes,particularly when they are modified to include appropriate labels. Theprobes can be used, for example, to determine the relative number and/orfunction of specific receptors, particularly the α4β2 or a 7 receptorsubtypes. The compounds of the present invention most preferably arelabeled with a radioactive isotopic moiety such as ¹¹C, ¹⁸F, ⁷⁶Br, ¹²³Ior ¹²⁵I, as discussed in PCT WO 01/82979 to Bencherif et al.

The administered compounds can be detected using known detection methodsappropriate for the label used. Examples of detection methods includeposition emission topography (PET) and single-photon emission computedtomography (SPECT). The radiolabels described above are useful in PET(e.g., ¹¹C, ¹⁸F or ⁷⁶Br) and SPECT (e.g., ¹²³I) imaging, with half-livesof about 20.4 minutes for ¹¹C, about 109 minutes for ¹⁸F, about 13 hoursfor ¹²³I, and about 16 hours for ⁷⁶Br. A high specific activity isdesired to visualize the selected receptor subtypes at non-saturatingconcentrations. The administered doses typically are below the toxicrange and provide high contrast images. The compounds are expected to becapable of administration in non-toxic levels. Determination of dose iscarried out in a manner known to one skilled in the art of radiolabelimaging. See, for example, U.S. Pat. No. 5,969,144 to London et al.

The compounds can be administered using known techniques. See, forexample, U.S. Pat. No. 5,969,144 to London et al. The compounds can beadministered in formulation compositions that incorporate otheringredients, such as those types of ingredients that are useful informulating a diagnostic composition. Compounds useful in accordancewith carrying out the present invention most preferably are employed informs of high purity. See U.S. Pat. No. 5,853,696 to Elmalch et al.

After the compounds are administered to a subject (e.g., a humansubject), the presence of that compound within the subject can be imagedand quantified by appropriate techniques in order to indicate thepresence, quantity, and functionality of selected nicotinic cholinergicreceptor subtypes. In addition to humans, the compounds can also beadministered to animals, such as mice, rats, dogs, and monkeys. SPECTand PET imaging can be carried out using any appropriate technique andapparatus. See Villemagne et al., In: Neuronal Nicotinic Receptors:Pharmacology and Therapeutic Opportunities, Arneric et al. (Eds.),235-250 (1998) and U.S. Pat. No. 5,853,696 to Elmalch et al. for adisclosure of representative imaging techniques.

The radiolabeled compounds bind with high affinity to selective nAChRsubtypes (e.g., α4β2 or α7) and preferably exhibit negligiblenon-specific binding to other nicotinic cholinergic receptor subtypes(e.g., those receptor subtypes associated with muscle and ganglia). Assuch, the compounds can be used as agents for noninvasive imaging ofnicotinic cholinergic receptor subtypes within the body of a subject,particularly within the brain for diagnosis associated with a variety ofCNS diseases and disorders.

In one aspect, the diagnostic compositions can be used in a method todiagnose disease in a subject, such as a human patient. The methodinvolves administering to that patient a detectably labeled compound asdescribed herein, and detecting the binding of that compound to selectednicotinic receptor subtypes (e.g., α7 receptor subtype). Those skilledin the art of using diagnostic tools, such as PET and SPECT, can use theradiolabeled compounds described herein to diagnose a wide variety ofconditions and disorders, including conditions and disorders associatedwith dysfunction of the central and autonomic nervous systems. Suchdisorders include a wide variety of CNS diseases and disorders,including Alzheimer's disease, Parkinson's disease, and schizophrenia.These and other representative diseases and disorders that can beevaluated include those that are set forth in U.S. Pat. No. 5,952,339 toBencherif et al., the contents of which are hereby incorporated byreference.

In another aspect, the diagnostic compositions can be used in a methodto monitor selective nicotinic receptor subtypes of a subject, such as ahuman patient. The method involves administering a detectably labeledcompound as described herein to that patient, and detecting the bindingof that compound to selected nicotinic receptor subtypes (e.g., the α7receptor subtype).

The following examples are provided to further illustrate the presentinvention, and should not be construed as limiting thereof.

V. BIOLOGICAL ASSAYS

Radioligand Binding at CNS nAChR

α4β2 Subtype

Rats (female, Sprague-Dawley), weighing 150-250 g, were maintained on a12 h light/dark cycle and were allowed free access to water and foodsupplied by PMI Nutrition International, Inc. Animals were anaesthetizedwith 70% CO2, then decapitated. Brains were removed and placed on anice-cold platform. The cerebral cortex was removed and placed in 20volumes (weight: volume) of ice-cold preparative buffer (137 mM NaCl,10.7 mM KCl, 5.8 mM KH2PO4, 8 mM Na2HPO4, 20 mM HEPES (free acid), 5 mMiodoacetamide, 1.6 mM EDTA, pH 7.4); PMSF, dissolved in methanol to afinal concentration of 100 μM, was added and the suspension washomogenized by Polytron. The homogenate was centrifuged at 18,000×g for20 min at 4° C. and the resulting pellet was re-suspended in 20 volumesof ice-cold water. After 60 min incubation on ice, a new pellet wascollected by centrifugation at 18,000×g for 20 min at 4° C.

The final pellet was re-suspended in 10 volumes of buffer and stored at−20° C. On the day of the assay, tissue was thawed, centrifuged at18,000×g for 20 min, and then re-suspended in ice-cold PBS (Dulbecco'sPhosphate Buffered Saline, 138 mM NaCl, 2.67 mM KCl, 1.47 mM KH₂PO₄, 8.1mM Na₂HPO₄, 0.9 mM CaCl₂, 0.5 mM MgCl₂, Invitrogen/Gibco, pH 7.4) to afinal concentration of approximately 4 mg protein/ml. Protein wasdetermined by the method of Lowry et al., J. Biol. Chem. 193: 265(1951), using bovine serum albumin as the standard.

The binding of [3H]nicotine was measured using a modification of themethods of Romano et al., Science 210: 647 (1980) and Marks et al., Mol.Pharmacol. 30: 427 (1986). The [3H]nicotine (Specific Activity=81.5Ci/mmol) was obtained from NEN Research Products. The binding of[³H]nicotine was measured using a 3 h incubation at 4° C. Incubationswere conducted in 48-well micro-titre plates and contained about 400 μgof protein per well in a final incubation volume of 300 μL. Theincubation buffer was PBS and the final concentration of [³H]nicotinewas 5 nM. The binding reaction was terminated by filtration of theprotein containing bound ligand onto glass fiber filters (GF/B, Brandel)using a Brandel Tissue Harvester at 4° C. Filters were soaked inde-ionized water containing 0.33% polyethyleneimine to reducenon-specific binding. Each filter was washed with ice-cold buffer (3×1ml). Non-specific binding was determined by inclusion of 10 μMnon-radioactive L-nicotine (Acros Organics) in selected wells.

The inhibition of [³H]nicotine binding by test compounds was determinedby including seven different concentrations of the test compound inselected wells. Each concentration was replicated in triplicate. IC₅₀values were estimated as the concentration of compound that inhibited 50percent of specific [3H]nicotine binding. Inhibition constants (Kivalues), reported in nM, were calculated from the IC₅₀ values using themethod of Cheng et al., Biochem. Pharmacol. 22: 3099 (1973).

α7 Subtype

Rats (female, Sprague-Dawley), weighing 150-250 g, were maintained on a12 h light/dark cycle and were allowed free access to water and foodsupplied by PMI Nutrition International, Inc. Animals were anaesthetizedwith 70% CO2, then decapitated. Brains were removed and placed on anice-cold platform. The hippocampus was removed and placed in 10 volumes(weight: volume) of ice-cold preparative buffer (137 mM NaCl, 10.7 mMKCl, 5.8 mM KH₂PO₄, 8 mM Na₂HPO₄, 20 mM HEPES (free acid), 5 mMiodoacetamide, 1.6 mM EDTA, pH 7.4); PMSF, dissolved in methanol to afinal concentration of 100 μM, was added and the tissue suspension washomogenized by Polytron. The homogenate was centrifuged at 18,000×g for20 min at 4° C. and the resulting pellet was re-suspended in 10 volumesof ice-cold water. After 60 min incubation on ice, a new pellet wascollected by centrifugation at 18,000×g for 20 min at 4° C. The finalpellet was re-suspended in 10 volumes of buffer and stored at −20° C. Onthe day of the assay, tissue was thawed, centrifuged at 18,000×g for 20min, and then re-suspended in ice-cold PBS (Dulbecco's PhosphateBuffered Saline, 138 mM NaCl, 2.67 mM KCl, 1.47 mM KH₂PO₄, 8.1 mMNa₂HPO₄, 0.9 mM CaCl₂, 0.5 mM MgCl₂, Invitrogen/Gibco, pH 7.4) to afinal concentration of approximately 2 mg protein/ml. Protein wasdetermined by the method of Lowry et al., J. Biol. Chem. 193: 265(1951), using bovine serum albumin as the standard.

The binding of [³H]MLA was measured using a modification of the methodsof Davies et al., Neuropharmacol. 38: 679 (1999). [³H]MLA (SpecificActivity=25-35 Ci/mmol) was obtained from Tocris. The binding of [³H]MLAwas determined using a 2 h incubation at 21° C. Incubations wereconducted in 48-well micro-titre plates and contained about 200 μg ofprotein per well in a final incubation volume of 300 pt. The incubationbuffer was PBS and the final concentration of [³H]MLA was 5 nM. Thebinding reaction was terminated by filtration of the protein containingbound ligand onto glass fiber filters (GF/B, Brandel) using a BrandelTissue Harvester at room temperature. Filters were soaked in de-ionizedwater containing 0.33% polyethyleneimine to reduce non-specific binding.Each filter was washed with PBS (3×1 ml) at room temperature.Non-specific binding was determined by inclusion of 50 μMnon-radioactive MLA in selected wells.

The inhibition of [³H]MLA binding by test compounds was determined byincluding seven different concentrations of the test compound inselected wells. Each concentration was replicated in triplicate. IC₅₀values were estimated as the concentration of compound that inhibited 50percent of specific [³H]MLA binding. Inhibition constants (Ki values),reported in nM, were calculated from the IC₅₀ values using the method ofCheng et al., Biochem. Pharmacol. 22: 3099-3108 (1973).

Determination of Dopamine Release

Dopamine release was measured using striatal synaptosomes obtained fromrat brain, according to the procedures set forth by Rapier et al., J.Neurochem. 54: 937 (1990). Rats (female, Sprague-Dawley), weighing150-250 g, were maintained on a 12 h light/dark cycle and were allowedfree access to water and food supplied by PMI Nutrition International,Inc. Animals were anaesthetized with 70% CO₂, then decapitated. Thebrains were quickly removed and the striata dissected. Striatal tissuefrom each of 2 rats was pooled and homogenized in ice-cold 0.32 Msucrose (5 ml) containing 5 mM HEPES, pH 7.4, using a glass/glasshomogenizer. The tissue was then centrifuged at 1,000×g for 10 min. Thepellet was discarded and the supernatant was centrifuged at 12,000×g for20 min. The resulting pellet was re-suspended in perfusion buffercontaining monoamine oxidase inhibitors (128 mM NaCl, 1.2 mM KH₂PO₄, 2.4mM KCl, 3.2 mM CaCl₂, 1.2 mM MgSO₄, 25 mM HEPES, 1 mM ascorbic acid,0.02 mM pargyline HCl and 10 mM glucose, pH 7.4) and centrifuged for 15min at 25,000×g. The final pellet was resuspended in perfusion buffer(1.4 ml) for immediate use.

The synaptosomal suspension was incubated for 10 min at 37° C. torestore metabolic activity. [³H]Dopamine ([³H]DA, specific activity=28.0Ci/mmol, NEN Research Products) was added at a final concentration of0.1 μM and the suspension was incubated at 37° C. for another 10 min.Aliquots of tissue (50 μl) and perfusion buffer (100 μl) were loadedinto the suprafusion chambers of a Brandel Suprafusion System (series2500, Gaithersburg, Md.). Perfusion buffer (room temperature) was pumpedinto the chambers at a rate of 3 ml/min for a wash period of 8 min. Testcompound (10 μM) or nicotine (10 μM) was then applied in the perfusionstream for 40 sec. Fractions (12 sec each) were continuously collectedfrom each chamber throughout the experiment to capture basal release andagonist-induced peak release and to re-establish the baseline after theagonist application. The perfusate was collected directly intoscintillation vials, to which scintillation fluid was added. [3H]DAreleased was quantified by scintillation counting. For each chamber, theintegrated area of the peak was normalized to its baseline.

Release was expressed as a percentage of release obtained with an equalconcentration of L-nicotine. Within each assay, each test compound wasreplicated using 2-3 chambers; replicates were averaged. Whenappropriate, dose-response curves of test compound were determined. Themaximal activation for individual compounds (E_(max)) was determined asa percentage of the maximal activation induced by L-nicotine. Thecompound concentration resulting in half maximal activation (EC₅₀) ofspecific ion flux was also defined.

Antagonism of dopamine release can also be evaluated using the assaysdescribed in Gradyet al., “Characterization of nicotinic receptormediated [³H]dopamine release from synaptosomes prepared from mousestriatum,” J. Neurochem. 59: 848-856 (1992) and Soliakov and Wonnacott,“Voltage-sensitive Ca2+ channels involved in nicotinic receptor-mediated[3H]dopamine release from rat striatal synaptosomes,” J. Neurochem.67:163-170 (1996).

Selectivity vs. Peripheral nAChRs

Interaction at the Human Muscle Subtype

Activation of muscle-type nAChR was established on the human clonal lineTE671/RD, which is derived from an embryonal rhabdomyosarcoma (Strattonet al., Carcinogen 10: 899 (1989)). These cells express receptors thathave pharmacological (Lukas, J. Pharmacol. Exp. Ther. 251: 175 (1989)),electrophysiological (Oswald et al., Neurosci. Lett. 96: 207 (1989)),and molecular biological profiles (Luther et al., J. Neurosci. 9: 1082(1989)) similar to the muscle-type nAChR.

TE671/RD cells were maintained in proliferative growth phase accordingto routine protocols (Bencherif et al., Mol. Cell. Neurosci. 2: 52(1991) and Bencherif et al., J. Pharmacol. Exp. Ther. 257: 946 (1991)).Cells were cultured in Dulbecco's modified Eagle's medium (Gibco/BRL)with 10% horse serum (Gibco/BRL), 5% fetal bovine serum (HyClone, LoganUtah), 1 mM sodium pyruvate, 4 mM L-Glutamine, and 50,000 unitspenicillin-streptomycin (Irvine Scientific). When cells were 80%confluent, they were plated to 6 well polystyrene plates (Costar).Experiments were conducted when the cells reached 100% confluency.

Nicotinic acetylcholine receptor (nAChR) function was assayed using⁸⁶Rb+ efflux according to the method described by Lukas et al., Anal.Biochem. 175: 212 (1988). On the day of the experiment, growth media wasgently removed from the well and growth media containing ⁸⁶Rubidiumchloride (106 μCi/ml) was added to each well. Cells were incubated at37° C. for a minimum of 3 h. After the loading period, excess ⁸⁶Rb+ wasremoved and the cells were washed twice with label-free Dulbecco'sphosphate buffered saline (138 mM NaCl, 2.67 mM KCl, 1.47 mM KH₂PO₄, 8.1mM Na₂HPO₄, 0.9 mM CaCl₂, 0.5 mM MgCl₂, Invitrogen/Gibco, pH 7.4),taking care not to disturb the cells. Next, cells were exposed to either100 μM of test compound, 100 μM of L-nicotine (Acros Organics) or bufferalone for 4 min. Following the exposure period, the supernatantcontaining the released ⁸⁶Rb+ was removed and transferred toscintillation vials. Scintillation fluid was added and releasedradioactivity was measured by liquid scintillation counting.

Within each assay, each point had 2 replicates, which were averaged. Theamount of ⁸⁶Rb+ release was compared to both a positive control (100 μML-nicotine) and a negative control (buffer alone) to determine thepercent release relative to that of L-nicotine.

When appropriate, dose-response curves of test compound were determined.The maximal activation for individual compounds (E_(max)) was determinedas a percentage of the maximal activation induced by L-nicotine. Thecompound concentration resulting in half maximal activation (EC₅₀) ofspecific ion flux was also determined.

Interaction at the Rat Ganglionic Subtype

Activation of rat ganglion nAChR was established on the pheochromocytomaclonal line PC12, which is a continuous clonal cell line of neural crestorigin, derived from a tumor of the rat adrenal medulla. These cellsexpress ganglion-like neuronal nicotinic receptors (see Whiting et al.,Nature 327: 515 (1987); Lukas, J. Pharmacol. Exp. Ther. 251: 175 (1989);Whiting et al., Mol. Brain Res. 10: 61 (1990)).

Rat PC12 cells were maintained in proliferative growth phase accordingto routine protocols (Bencherif et al., Mol. Cell. Neurosci. 2: 52(1991) and Bencherif et al., J. Pharmacol. Exp. Ther. 257: 946 (1991)).Cells were cultured in Dulbecco's modified Eagle's medium (Gibco/BRL)with 10% horse serum (Gibco/BRL), 5% fetal bovine serum (HyClone, LoganUtah), 1 mM sodium pyruvate, 4 mM L-Glutamine, and 50,000 unitspenicillin-streptomycin (Irvine Scientific). When cells were 80%confluent, they were plated to 6 well Nunc plates (Nunclon) and coatedwith 0.03% poly-L-lysine (Sigma, dissolved in 100 mM boric acid).Experiments were conducted when the cells reached 80% confluency.

Nicotinic acetylcholine receptor (nAChR) function was assayed using⁸⁶Rb+ efflux according to a method described by Lukas et al., Anal.Biochem. 175: 212 (1988). On the day of the experiment, growth media wasgently removed from the well and growth media containing ⁸⁶Rubidiumchloride (106 μCi/ml) was added to each well. Cells were incubated at37° C. for a minimum of 3 h. After the loading period, excess ⁸⁶Rb+ wasremoved and the cells were washed twice with label-free Dulbecco'sphosphate buffered saline (138 mM NaCl, 2.67 mM KCl, 1.47 mM KH₂PO₄, 8.1mM Na₂HPO₄, 0.9 mM CaCl₂, 0.5 mM MgCl₂, Invitrogen/Gibco, pH. 7.4),taking care not to disturb the cells. Next, cells were exposed to either100 μM of test compound, 100 μM of nicotine or buffer alone for 4 min.Following the exposure period, the supernatant containing the released⁸⁶Rb+ was removed and transferred to scintillation vials. Scintillationfluid was added and released radioactivity was measured by liquidscintillation counting.

Within each assay, each point had 2 replicates, which were averaged. Theamount of ⁸⁶Rb+ release was compared to both a positive control (100 μMnicotine) and a negative control (buffer alone) to determine the percentrelease relative to that of L-nicotine.

When appropriate, dose-response curves of test compound were determined.The maximal activation for individual compounds (E_(max)) was determinedas a percentage of the maximal activation induced by L-nicotine. Thecompound concentration resulting in half maximal activation (EC₅₀) ofspecific ion flux was also determined.

Interaction at the Human Ganglionic Subtype

The cell line SH-SY5Y is a continuous line derived by sequentialsubcloning of the parental cell line, SK-N-SH, which was originallyobtained from a human peripheral neuroblastoma. SH-SY5Y cells express aganglion-like nAChR (Lukas et al., Mol. Cell. Neurosci. 4: 1 (1993)).Human SH-SY5Y cells were maintained in proliferative growth phaseaccording to routine protocols (Bencherif et al., Mol. Cell. Neurosci.2: 52 (1991) and Bencherif et al., J. Pharmacol. Exp. Ther. 257: 946(1991)). Cells were cultured in Dulbecco's modified Eagle's medium(Gibco/BRL) with 10% horse serum (Gibco/BRL), 5% fetal bovine serum(HyClone, Logan Utah), 1 mM sodium pyruvate, 4 mM L-Glutamine, and50,000 units penicillin-streptomycin (Irvine Scientific). When cellswere 80% confluent, they were plated to 6 well polystyrene plates(Costar). Experiments were conducted when the cells reached 100%confluency. Nicotinic acetylcholine receptor (nAChR) function wasassayed using ⁸⁶Rb+ efflux according to a method described by Lukas etal., Anal. Biochem. 175: 212 (1988). On the day of the experiment,growth media was gently removed from the well and growth mediacontaining ⁸⁶Rubidium chloride (106 μCi/ml) was added to each well.Cells were incubated at 37° C. for a minimum of 3 h. After the loadingperiod, excess ⁸⁶Rb+ was removed and the cells were washed twice withlabel-free Dulbecco's phosphate buffered saline (138 mM NaCl, 2.67 mMKCl, 1.47 mM KH₂PO₄, 8.1 mM Na₂HPO₄, 0.9 mM CaCl₂, 0.5 mM MgCl₂,Invitrogen/Gibco, pH 7.4), taking care not to disturb the cells. Next,cells were exposed to either 100 μM of test compound, 100 μM ofnicotine, or buffer alone for 4 min. Following the exposure period, thesupernatant containing the released ⁸⁶Rb+ was removed and transferred toscintillation vials. Scintillation fluid was added and releasedradioactivity was measured by liquid scintillation counting.

Within each assay, each point had 2 replicates, which were averaged. Theamount of 86Rb+ release was compared to both a positive control (100 μMnicotine) and a negative control (buffer alone) to determine the percentrelease relative to that of L-nicotine.

When appropriate, dose-response curves of test compound were determined.The maximal activation for individual compounds (E_(max)) was determinedas a percentage of the maximal activation induced by L-nicotine. Thecompound concentration resulting in half maximal activation (EC₅₀) ofspecific ion flux was also defined.

VI. EXAMPLES

The following synthetic examples are provided to illustrate the presentinvention and should not be construed as limiting the scope thereof. Inthese examples, all parts and percentages are by weight, unlessotherwise noted. Reaction yields are reported in mole percentage.

Example 1

Example No. 1 is the pair of isomers,3-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene dihydrochloride and3-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene dihydrochloride, which wereprepared in accordance with the following techniques:

4-Iodo-6-oxabicyclo[3.2.1]octan-7-one

To a suspension of 3-cyclohexenecarboxylic acid (5.0 g, 40 mmol) inwater (200 ml) was added, with vigorous stirring, sodium bicarbonate(9.90 g, 118 mmol). A solution of potassium iodide (39.0 g, 235 mmol) inwater (125 ml) was prepared, and to this iodine (10 g, 40 mmol) wasadded to give a brown solution. This solution was added in one portionto the vigorously stirring solution of cyclohexenecarboxylate. Themixture was stirred at room temperature in the dark for 18 h. Theresulting yellow solid was collected by filtration. The damp solid wasdissolved in chloroform (150 ml) and washed with sodium thiosulfatesolution (2×25 ml), and then with brine (25 ml). It was dried overmagnesium sulfate, filtered and concentrated by rotary evaporation toafford iodolactone (8.5 g, 84%, m.p. 133-134° C.).

6-Oxabicyclo[3.2.1]oct-3-en-7-one

To 4-iodo-6-oxabicyclo[3.2.1]octan-7-one (8.00 g, 31.7 mmol) in benzene(100 ml) was added 1,8-diazabicyclo[5.4.0]undec-7-ene (7.9 g, 32 mmol)under nitrogen, and the mixture was heated under reflux for 6 h. Thewhite precipitate was filtered off from the cooled solution and washedwith ether (100 ml). The combined filtrates were washed with water (50ml), 1N HCl (50 ml), and brine (25 ml), and then dried over magnesiumsulfate. The solvents were removed by rotary evaporation to afford thealkene as a light brown oil (2.6 g, 66%).

N-benzyl-5-hydroxycyclohex-3-enecarboxamide

To 6-oxabicyclo[3.2.1]oct-3-en-7-one (2.6 g, 21 mmol) in xylenes (50 ml)under nitrogen was added benzylamine (3.42 g, 32 mmol). The mixture washeated under reflux for 16 h, then cooled to room temperature. The heavywhite precipitate was collected by filtration, and recrystallized fromdichloromethane/hexane to give the amide as a white solid (3.8 g, 78%,m.p. 127-128° C.).

5-(Benzylaminomethyl)cyclohex-2-enol

To a suspension of lithium aluminum hydride (1.50 g, 40.5 mmol) in dryTHF (100 ml), cooled in an ice bath, was added drop-wise a solution ofN-benzyl-5-hydroxycyclohex-3-enecarboxamide (4.6 g, 20 mmol) in THF (60ml) over 30 min. The cold bath was removed and the reaction was heatedunder reflux for 16 h. Then the mixture was cooled in an ice bath anddiluted with ether (200 ml), then carefully quenched with water (1.5ml), 1N sodium hydroxide (4 ml) and water (1.5 ml), successively. Afterstirring for 45 min, the white suspension was filtered through a glassfrit, and the residue was washed with ether. Removal of solvents byrotary evaporation gave the alcohol as a clear, colorless oil (3.8 g,88%).

6-Benzyl-6-azabicyclo[3.2.1]octan-3-one

To a solution of 5-(benzylaminomethyl)cyclohex-2-enol (3.80 g, 17.5mmol) in dry dichloromethane (150 ml) was added activated manganesedioxide (18.0 g, 210 mmol) in one portion. The mixture was stirredvigorously under nitrogen for 2 h. The yellow solution was filteredthrough Celite and the solids were washed with dichloromethane (2×50ml). The combined filtrates were concentrated by rotary evaporation togive an orange oil, which solidified on brief standing. The solid wasrecrystallized from hot hexane/ether to afford the ketone as anoff-white solid (2.6 g, 68%).

t-Butyl 3-oxo-6-azabicyclo[3.2.1]octane-6-carboxylate

To a solution of 6-benzyl-6-azabicyclo[3.2.1]octan-3-one (1.2 g, 5.6mmol) in dry dichloromethane (20 ml), cooled in an ice bath undernitrogen, was added drop-wise chloroethyl chloroformate (Acros, 0.64 ml,7.2 mmol). The mixture was stirred 10 min at 0° C., then warmed to roomtemperature and stirred 1.5 h. The mixture was concentrated to drynessby rotary evaporation and the residue was dissolved in methanol (15 ml).The resulting solution was heated under reflux for 2 h, thenconcentrated to dryness by rotary evaporation and the residue wasre-suspended in dry dichloromethane (20 ml). The suspension was cooledin an ice bath, then triethylamine (2.1 ml, 15 mmol) was added, followedby di-t-butyl dicarbonate (1.31 g, 6.01 mmol). The mixture was allowedto warm to room temperature and stir over the weekend (64 h). Thereaction mixture was diluted with dichloromethane and washed with water,1N HCl, water, and brine (10 ml each). The organic layer was dried overmagnesium sulfate, filtered, and concentrated by rotary evaporation togive a yellow oil, which solidified on standing to a waxy solid. Theproduct contained minor impurities and was purified by columnchromatography, using a hexane/ethyl acetate gradient (0-30% ethylacetate) as eluent, to give the product as a pale yellow, waxy solid(0.80 g, 63%).

t-Butyl3-trifluoromethanesulfonyloxy-6-azabicyclo[3.2.1]oct-2-ene-6-carboxylateand t-butyl3-trifluoromethanesulfonyloxy-6-azabicyclo[3.2.1]oct-3-ene-6-carboxylate

To a solution of dry diisopropylamine (0.15 ml, 1.1 mmol) in dry THF (15ml), cooled to ±78° C. under nitrogen, was added drop-wise a solution of2.4 M n-butyllithium in hexane (0.46 ml, 1.1 mmol). After 15 min, asolution of t-butyl 3-oxo-6-azabicyclo[3.2.1]octane-6-carboxylate (225mg, 1 mmol) in THF (3 ml) was added drop-wise. After stirring 15 min at±78° C., 2-(N,N-bis(trifluoromethylsulfonyl)amino-5-chloropyridine (431mg, 1.10 mmol) was added in one portion. The reaction was allowed towarm to around 0° C. over 1.5 h, at which time it was quenched byaddition of a saturated solution of sodium bicarbonate (25 ml). Themixture was extracted with ether (4×15 ml) and the organic extractscombined and washed with 1N HCl, water, saturated sodium bicarbonatesolution and brine (10 ml each) and dried over magnesium sulfate.Filtration and concentration by rotary evaporation gave a viscous,orange oil. This was dissolved in chloroform, adsorbed onto 5 g silicagel, dried, and eluted on an ISCO combiflash system (10 g SiO2 column,20 ml/min flow, 0-50% ethyl acetate/hexane over 20 min). The fractionscorresponding to the desired product (higher Rf, non-UV active) werepooled and concentrated by rotary evaporation to afford the mixture ofenol triflates as a pale yellow oil (260 mg, 73%).

3-(3-Pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene dihydrochloride and3-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene dihydrochloride

To a solution of the mixture of enol triflates (1.0 g, 2.8 mmol) indimethoxyethane (20 ml) was added a saturated solution of sodiumcarbonate (5 ml), lithium chloride (0.42 g, 10 mmol) and3-pyridinylboronic acid (510 mg, 4.20 mmol). The reaction mixture wasfilled with nitrogen, then palladium tetrakis(triphenylphosphine)catalyst was added (200 mg). The reaction mixture was stirred vigorouslyand heated under reflux for 4 h. The dark mixture was filtered through aCelite pad into 50% aqueous ammonium hydroxide solution (25 ml). Themixture was extracted with ethyl acetate (2×25 ml), and then theorganics were washed with brine (2×15 ml) and dried over sodium sulfate.Concentration by rotary evaporation gave a dark oil, which was purifiedby column chromatography, using hexane-ethyl acetate (2:1) as eluent, toafford a brown oil (750 mg). The oil was dissolved in methanol (5 ml)and was treated with 4 N HCl in dioxane (1 ml) at room temperature for 2h. Removal of solvent by rotary evaporation left a residue, which wasdissolved in methanol and treated with ammonium hydroxide, thenconcentrated by rotary evaporation. The resulting oil was trituratedwith chloroform and the extract was purified by column chromatography onan ISCO 10 g silica gel column, using a gradient ofmethanol/dichloromethane (0-10% methanol with 1% ammonium hydroxide) aseluent. This separated the two regioisomers.

The higher Rf fractions were pooled, concentrated, treated withmethanolic HCl, and concentrated to give3-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene dihydrochloride, (96 mg),m.p.=210-212° C.

The lower Rf fractions were pooled, concentrated, treated withmethanolic HCl, and concentrated to give3-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene dihydrochloride, (28 mg).

Example 2

Example No. 2 is 3-(3-pyridinyl)-6-azabicyclo[3.2.1]octane, which wasprepared in accordance with the following techniques:

3-(3-pyridinyl)-6-azabicyclo[3.2.1]octane

To a solution of a mixture of t-butyl3-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene-6-carboxylate and t-butyl3-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene-6-carboxylate (150 mg) inmethanol (5 ml) was added catalytic 10% Pd/C and the mixture wassubjected to hydrogenolysis (45 psi) for 48 h. The reaction was filteredthrough Celite and concentrated by rotary evaporation, and then theresidue was taken up in dichloromethane (1 ml) and treated withtrifluoroacetic acid (2 ml). After 3 h, the mixture was concentrated todryness by rotary evaporation, partitioned between water anddichloromethane, and the organic layer discarded. The aqueous layer wasmade basic with sodium hydroxide and extracted with dichloromethane.After drying over sodium sulfate, the filtered solution was concentratedto dryness by rotary evaporation and the residue purified by columnchromatography, using a methanol/dichloromethane gradient (0-10%methanol with 1% ammonium hydroxide) as eluent. The product fractionswere pooled and concentrated to give the desired product (20 mg). It wasthen re-chromatographed (same conditions) to give the free base (10 mg)as a brown oil.

Example 3

Example No. 3 is the pair of regioisomers,3-(6-methoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene dihydrochlorideand 3-(6-methoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-enedihydrochloride, which were prepared in accordance with the followingtechniques:

3-(6-Methoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene dihydrochlorideand 3-(6-methoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-enedihydrochloride

To a solution of a mixture of t-butyl3-trifluoromethanesulfonyloxy-6-azabicyclo[3.2.1]oct-2-ene-6-carboxylateand t-butyl3-trifluoromethanesulfonyloxy-6-azabicyclo[3.2.1]oct-3-ene-6-carboxylate(120 mg, 0.336 mmol) in dimethoxyethane (2 ml) was added a saturatedsolution of sodium carbonate (0.5 ml), lithium chloride (42 mg, 1 mmol)and 2-methoxy-5-pyridinylboronic acid 1,3-propanediol cyclic ester (96mg, 0.5 mmol). The reaction flask was evacuated under high vacuum andfilled with nitrogen three times, then palladiumtetrakis(triphenylphosphine) catalyst was added (20 mg). The reactionmixture was stirred vigorously and heated under reflux for 2.5 h. Thedark mixture was diluted with ethyl acetate (20 ml) and filtered througha Celite pad into 50% aq. ammonium hydroxide solution (20 ml). Themixture was extracted with ethyl acetate (2×15 ml) and then the combinedorganics were washed with brine (2×15 ml) and dried over magnesiumsulfate. Concentration by rotary evaporation gave a dark oil, which waspurified by column chromatography, using a hexane/ethyl acetate gradient(0-30% ethyl acetate) as eluent, to afford the product as a brown oil(65 mg, 63%). A solution of the resulting mixture of regioisomers indioxane (1 ml) was treated with 4N HCl in dioxane (0.5 ml) at roomtemperature for 20 min. Removal of solvent by rotary evaporation left aresidue, which was recrystallized from isopropanol-ether to give theproduct as a pale yellow foam (GC: 86% purity, 2 isomers 61% and 25%respectively).

Example 4

Example No. 4 is the pair of regioisomers,3-(5-phenoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene dihydrochlorideand 3-(5-phenoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-enedihydrochloride, which were prepared in accordance with the followingtechniques:

3-(5-Phenoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene dihydrochlorideand 3-(5-phenoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-enedihydrochloride

To a solution of a mixture of t-butyl3-trifluoromethanesulfonyloxy-6-azabicyco[3.2.1]oct-2-ene-6-carboxylateand t-butyl3-trifluoromethanesulfonyloxy-6-azabicyco[3.2.1]oct-3-ene-6-carboxylate(144 mg, 0.40 mmol) in of dimethoxyethane (2 ml) was added a saturatedsolution of sodium carbonate (0.5 ml), lithium chloride (50 mg, 1.2mmol) and 5-phenoxy-3-pyridinylboronic acid (128 mg, 0.60 mmol). Thereaction flask was evacuated under high vacuum and filled with nitrogenthree times, then palladium tetrakis(triphenylphosphine) catalyst wasadded (50 mg). The reaction mixture was stirred vigorously and heatedunder reflux for 2.5 h. The dark mixture was diluted with ethyl acetate(20 ml) and filtered through a Celite pad into 50% aq. ammoniumhydroxide solution (20 ml). The mixture was extracted with ethyl acetate(2×15 ml) and then the combined organics were washed with brine (2×15ml) and dried over magnesium sulfate. Concentration by rotaryevaporation gave a dark oil, which was purified by columnchromatography, using a hexane/ethyl acetate gradient (0-30% ethylacetate) as eluent, to afford the product as a brown oil. A solution ofthe resulting pair of regioisomers in dioxane (1 ml) was treated with 4N HCl in dioxane (0.5 ml) at room temperature for 20 min. Removal ofsolvent by rotary evaporation left a residue, which was recrystallizedfrom isopropanol/ether to give a mixture of the desired pair ofregioisomers (32 mg) as a pale yellow foam.

Example 5

Example No. 5 is the pair of isomers6-methyl-3-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene and6-methyl-3-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene, which wereprepared in accordance with the following techniques:

6-Methyl-3-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene and6-methyl-3-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene

To a suspension of a mixture of3-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene dihydrochloride and3-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene dihydrochloride (50 mg,0.18 mmol) in dichloroethane (3 ml) was added aqueous 40% formaldehyde(75 mg, 1 mmol), followed by sodium triacetoxyborohydride (215 mg, 1mmol). The mixture was stirred overnight at room temperature and thenconcentrated by rotary evaporation. The residue was dissolved inmethylene chloride and saturated sodium bicarbonate was added. Thephases were separated and the organics was washed with brine, dried overmagnesium sulfate, and concentrated by rotary evaporation. The residuewas filtered through a plug of silica, eluting withmethanol/dichloromethane (10% methanol with 1% ammonium hydroxide), togive a mixture of the desired pair of regioisomers (15 mg) as a paleyellow oil.

Example 6

Example No. 6 is the pair of isomers3-(5-phenyl-3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene dihydrochlorideand 3-(5-phenyl-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-enedihydrochloride, which were prepared in accordance with the followingtechniques:

3-(5-Phenyl-3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene dihydrochlorideand 3-(5-phenyl-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-enedihydrochloride

To a solution of a mixture of t-butyl3-trifluoromethanesulfonyloxy-6-azabicyco[3.2.1]oct-2-ene-6-carboxylateand t-butyl3-trifluoromethanesulfonyloxy-6-azabicyco[3.2.1]oct-3-ene-6-carboxylate(72 mg, 0.2 mmol) in dimethoxyethane (1 ml) was added a saturatedsolution of sodium carbonate (0.3 ml), lithium chloride (25 mg, 0.6mmol) and 5-phenyl-3-pyridinylboronic acid (60 mg, 0.3 mmol). Thereaction flask was evacuated under high vacuum and filled with nitrogenthree times, then palladium tetrakis(triphenylphosphine) catalyst wasadded (23 mg). The reaction mixture was stirred vigorously and heatedunder reflux for 2.5 h. The dark mixture was diluted with ethyl acetate(20 ml) and filtered through a Celite pad into 50% aq. ammoniumhydroxide solution (20 ml). The mixture was extracted with ethyl acetate(2×15 ml) and then the combined organics were washed with brine (2×15ml) and dried over magnesium sulfate. Concentration by rotaryevaporation gave a dark oil, which was purified by columnchromatography, using a hexane/ethyl acetate gradient (0-30% ethylacetate) as eluent, to afford the product as a brown oil. A solution ofthe resulting pair of regioisomers in dioxane (1 ml) was treated with 4N HCl in dioxane (0.5 ml) at room temperature for 20 min. Removal ofsolvent by rotary evaporation left a residue, which was recrystallizedfrom isopropanol/ether to give a mixture of the desired pair ofregioisomers (11 mg) as a pale yellow foam.

Example 7

Example No. 7 is the pair of isomers3-(5-isopropoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-enedihydrochloride and3-(5-isopropoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-enedihydrochloride, which were prepared in accordance with the followingtechniques:

3-(5-Isopropoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-enedihydrochloride and3-(5-isopropoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-enedihydrochloride

To a solution of a mixture of t-butyl3-trifluoromethanesulfonyloxy-6-azabicyco[3.2.1]oct-2-ene-6-carboxylateand t-butyl3-trifluoromethanesulfonyloxy-6-azabicyco[3.2.1]oct-3-ene-6-carboxylate(120 mg, 0.336 mmol) in dimethoxyethane (2 ml) was added a saturatedsolution of sodium carbonate (0.5 ml), lithium chloride (42 mg, 1 mmol)and 5-isopropoxy-3-pyridinylboronic acid (130 mg, 0.5 mmol). Thereaction flask was evacuated under high vacuum and filled with nitrogenthree times, then palladium tetrakis(triphenylphosphine) catalyst wasadded (20 mg). The reaction mixture was stirred vigorously and heatedunder reflux for 2.5 h. The dark mixture was diluted with ethyl acetate(20 ml) and filtered through a Celite pad into 50% aq. ammoniumhydroxide solution (20 ml). The mixture was extracted with ethyl acetate(2×15 ml) and then the combined organics were washed with brine (2×15ml) and dried over magnesium sulfate. Concentration by rotaryevaporation gave a dark oil, which was purified by columnchromatography, using a hexane/ethyl acetate gradient (0-30% ethylacetate) as eluent, to afford the product as a brown oil. A solution ofthe resulting regioisomers in dioxane (1 ml) was treated with 4 N HCl indioxane (0.5 ml) at room temperature for 20 min. Removal of solvent byrotary evaporation left a residue, which was recrystallized fromisopropanol/ether to give a mixture of the desired pair of regioisomers(35 mg) as a yellow foam.

Example 8

Example No. 8 is 4-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-enedihydrochloride, which was prepared in accordance with the followingtechniques:

6-Benzyl-6-azabicyclo[3.2.1]oct-3-en-7-one

To a solution of N-benzyl-5-hydroxycyclohex-3-enecarboxamide (3.0 g, 13mmol) in chloroform (10 ml) was added drop-wise thionyl chloride (5.0ml, 68 mmol). The mixture turned orange and foamed vigorously, thenfaded gradually to a nearly colorless solution over a 30 min period. Themixture was cautiously treated with water, and when foaming stopped,transferred to a separatory funnel. The chloroform layer washed withwater, brine, dried over magnesium sulfate and concentrated to a paleyellow solid. The crude product was dissolved in THF (20 ml) and addedto a solution of potassium t-butoxide (1.8 g, 15 mmol) in THF (30 ml).The mixture was stirred at room temperature overnight. The reactionmixture was diluted with ethyl acetate, washed with water and brine,dried over sodium sulfate and concentrated by rotary evaporation to anacrid-smelling yellow oil (200 mg). Purification by columnchromatography, using a gradient of hexane/ethyl acetate (20-50% ethylacetate) as eluent, gave the clean lactam as a pale yellow oil (1.4 g,51%).

8-Benzyl-3-oxa-8-azatricyclo[4.2.1.02.4]nonan-7-one

To a solution of 6-benzyl-6-azabicyclo[3.2.1]oct-3-en-7-one (1.0 g, 4.7mmol) in chloroform (50 ml) cooled in an ice bath was addedmeta-chloroperbenzoic acid (1.22 g, 7.0 mmol) in 3 portions over 5 min.The reaction mixture was allowed to warm to room temperature and stirredovernight. The resulting clear solution was treated cautiously withdilute aqueous sodium thiosulfate solution to reduce any excessmeta-chloroperbenzoic acid, and the layers separated. The organic layerwas washed with saturated sodium bicarbonate, water and brine, and driedover sodium sulfate. The solvent was removed by rotary evaporation togive the epoxide as a viscous oil, which solidified on brief standing.It was used without further purification the next step.

6-Benzyl-6-azabicyclo[3.2.1]octan-4-ol

To a suspension of lithium aluminum hydride (185 mg, 4.87 mmol) in THF(50 ml) cooled to 0° C. was added drop-wise a solution of8-benzyl-3-oxa-8-azatricyclo[4.2.1.02.4]nonan-7-one (1.15 g, 5.02 mmol)in THF (5 ml). The reaction was allowed to stir overnight at roomtemperature, then cooled in an ice bath and diluted with ether (50 ml).The reaction was quenched cautiously with water (0.2 ml), 1 M sodiumhydroxide (0.3 ml) and water (0.2 ml), successively. After stirring for1 h, the suspension was filtered, and the filtrate was concentrated byrotary evaporation to give the amino alcohol as a viscous yellow oil(0.90 g, 83%).

t-Butyl 4-hydroxy-6-azabicyclo[3.2.1]octane-6-carboxylate

To a solution of 6-benzyl-6-azabicyclo[3.2.1]octan-4-ol (0.90 g, 4.2mmol) in methanol (50 ml) was added 10% Pd/C (200 mg) and a few drops of12 N HCl. The mixture was subjected to hydrogenolysis for 48 h (45 psiof hydrogen) on a Parr apparatus. The mixture was filtered throughCelite and the filtrate was concentrated by rotary evaporation to yielda sticky yellow oil, which was then suspended in dichloromethane (25 ml)and cooled in an ice bath. Triethylamine (1.4 ml, 10 mmol) was added,followed by di-t-butyl dicarbonate (1.09 g, 5.00 mmol), and the mixturewas stirred overnight. The reaction mixture was washed with water, 1 NHCl and brine (2×15 ml each), dried over magnesium sulfate andconcentrated by rotary evaporation to a sticky solid. The residue waspurified by column chromatography, using a hexane/ethyl acetate gradient(0-50% ethyl acetate) as eluent, to give the alcohol as a white solid(400 mg, 43%).

t-Butyl 4-oxo-6-azabicyclo[3.2.1]octane-6-carboxylate

To a solution of t-butyl4-hydroxy-6-azabicyclo[3.2.1]octane-6-carboxylate (800 mg, 3.52 mmol) indry dichloromethane (75 ml) was added Celite (2 g), sodium acetate (0.82g, 10 mmol) and pyridinium chlorochromate (1.1 g, 5.1 mmol). The mixturewas stirred under nitrogen for 66 h. The dark suspension was dilutedwith ether (50 ml) and filtered through a plug of silica gel to give alight brown solution. Removal of solvent by rotary evaporation andpurification by column chromatography of the residue, using amethanol/dichloromethane gradient (0-10% methanol) as eluent, gave theketone as a pale yellow oil (770 mg, 96%).

t-Butyl4-trifluoromethanesulfonyloxy-6-azabicyclo[3.2.1]oct-3-ene-6-carboxylate

To a solution of diisopropylamine (0.42 ml, 3.0 mmol) in dry THF (20 ml)was added 2.5 M n-butyllithium (1.2 ml, 3.0 mmol) drop-wise at −78° C.After 15 min, t-butyl 4-oxo-6-azabicyclo[3.2.1]octane-6-carboxylate inTHF (5 ml) was added drop-wise. The pale orange reaction mixture wasstirred at −78° C. for 45 min, then treated with2-(N,N-bis(trifluoromethylsulfonyl)amino-5-chloropyridine (0.82 g, 2.1mmol) in one portion. The reaction was allowed to warm slowly to −10° C.over 1.5 h. The reaction was quenched by the addition of saturatedammonium chloride solution (10 ml). The mixture was extracted with ethylacetate (3×15 ml) and the combined extracts were washed with 1 N HCl,10% potassium hydroxide solution, and brine (2×10 ml each) insuccession. The dried extracts were filtered and concentrated by rotaryevaporation, and the residue was purified by column chromatography,using a hexane/ethyl acetate gradient (0-50% ethyl acetate) as eluent,to give the triflate as a yellow oil (400 mg, 56%).

4-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene dihydrochloride

To a solution of t-butyl4-trifluoromethanesulfonyloxy-6-azabicyclo[3.2.1]oct-3-ene-6-carboxylate(100 mg, 0.28 mmol) in dimethoxyethane (2 ml) was added a saturatedsolution of sodium carbonate (0.5 ml), lithium chloride (36 mg, 0.84mmol) and 3-pyridinylboronic acid 1,3-propanediol cyclic ester (68 mg,0.42 mmol). The reaction mixture was evacuated under high vacuum andfilled with nitrogen three times, then palladiumtetrakis(triphenylphosphine) catalyst (20 mg) was added. The reactionmixture was stirred vigorously and heated under reflux for 0.5 h. Thedark mixture was diluted with ethyl acetate (20 ml) and filtered througha Celite pad into 50% aqueous ammonium hydroxide solution (10 ml). Themixture was extracted with ethyl acetate (2×15 ml), the combinedorganics washed with brine (2×15 ml), and dried over magnesium sulfate.Concentration by rotary evaporation gave a dark oil, which was purifiedby column chromatography, using a hexane/ethyl acetate gradient aseluent (0-30% ethyl acetate), to afford the product as a colorless oil(60 mg, 75%). A solution of the oil in dioxane (1 ml) was treated with4N HCl in dioxane (0.5 ml) at room temperature for 20 min. Removal ofsolvent by rotary evaporation left a residue, which was recrystallizedfrom isopropanol/ether to give the dihydrochloride salt as a pale yellowpowder (34 mg, 63%).

Example 9

Example No. 9 is 6-(3-pyridinyl)-3-azabicyclo[3.2.1]oct-6-enedihydrochloride, which was prepared in accordance with the followingtechniques:

2-Chlorobicyclo[2.2.1]hept-5-ene-2-carbonitrile

To a solution of 2-chloroacrylonitrile (50.0 g, 571 mmol) in toluene(150 ml) was slowly added cyclopentadiene (37.7 g, 571 mmol). Thereaction was stirred for 60 h at ambient temperature under a nitrogenatmosphere. The reaction was then concentrated by rotary evaporation toremove the majority of the toluene. The compound was purified by vacuumdistillation (100-150° C., 15 mm Hg) to afford the nitrile as a whitesolid (49.7 g, 56.5%).

Bicyclo[2.2.1]hept-5-en-2-one

To a stirring solution of potassium hydroxide (85 g) in water (30 ml)was added drop-wise a solution of2-chlorobicyclo[2.2.1]hept-5-ene-2-carbonitrile in DMSO (450 ml). Thereaction turned red as the nitrile was added. The mixture was stirredfor 48 h. Water (500 ml) was added, then distilled off (70-100° C., 15mm Hg) which brought the ketone with it. This steam distillation wasperformed a second time (another 500 ml of water). The distilledfractions were combined, extracted with diethyl ether (3×200 ml), driedover sodium sulfate, filtered and concentrated. This compound wasdistilled once more (90° C., 15 mm Hg) to yield the ketone as a clear,colorless oil (26.6 g, 76%).

Bicyclo[2.2.1]hept-5-en-2-one ethylene ketal

To a stirring solution of bicyclo[2.2.1]hept-5-en-2-one (14.6 g, 135mmol) in benzene (250 ml) was added p-toluenesulfonic acid (2.59 g, 13.6mmol) and ethylene glycol (15.1 g, 271 mmol). The mixture was thenrefluxed for 60 h under nitrogen using a Dean Stark trap. After thereaction was cooled to ambient temperature, it was stirred withsaturated sodium bicarbonate (100 ml) for 30 min. The layers wereseparated and the aqueous phase extracted with ethyl acetate (1×100 ml).The organic extractions were then combined, dried over sodium sulfate,filtered and concentrated to yield the ketal as a clear, colorless oil(18.1 g, 88.1%).

6,8-Bis(hydroxymethyl)-1,4-dioxaspiro[4.4]nonane

A solution of bicyclo[2.2.1]hept-5-en-2-one ethylene ketal (7.04 g, 46.3mmol) in 30% methanol/dichloromethane (200 ml) was subjected toozonolysis for 45 min (10 min past the point at which the reactionturned blue) at −78° C. Nitrogen gas was then passed through thesolution until it again turned clear. At this point, sodium borohydride(5.25 g, 139 mmol) was added in one portion. The reaction was thenslowly allowed to come to room temperature while stirring undernitrogen. After 18 h the reaction was concentrated by rotaryevaporation. Then saturated ammonium chloride (25 ml) was added, and thesolution extracted with chloroform (5×75 ml). The organic extracts werecombined, dried over sodium sulfate, filtered and concentrated to yieldthe diol as a clear, colorless oil (5.66 g, 65.1%).

6,8-Bis(methylsulfonyloxymethyl)-1,4-dioxaspiro[4.4]nonane

6,8-Bis(hydroxymethyl)-1,4-dioxaspiro[4.4]nonane (8.18 g, 43.5 mmol) wasdissolved in dichloromethane (200 ml) and chilled to 0° C. To thechilled solution was added 4-dimethylaminopyridine (0.53 g, 4.4 mmol)and distilled triethylamine (18.2 ml, 131 mmol). Then methanesulfonylchloride (7.41 ml, 11.0 g, 95.7 mmol) was added drop-wise via syringeover 10 min and the reaction was allowed to come to ambient temperatureand stir for 18 h under nitrogen. The reaction was quenched withsaturated sodium bicarbonate (25 ml) and stirred for 30 min. Afterstirring, the layers were separated and the aqueous phase extracted withdichloromethane (2×50 ml). The organics were combined, dried over sodiumsulfate, filtered and concentrated to yield a reddish brown oil (14.9,99.4%).

3-Azabicyclo[3.2.1]octan-6-one ethylene ketal

6,8-Bis(methanesulfonyloxymethyl)-1,4-dioxaspiro[4.4]nonane (14.90 g,43.3 mmol) was suspended in aqueous ammonia (35%, 150 ml) and heated for18 h at 60° C. The reaction was cooled to ambient temperature andconcentrated by rotary evaporation. The residue was treated withsaturated sodium chloride solution (50 ml) and extracted with chloroform(3×50 ml). The organic extracts were combined, dried over sodiumsulfate, filtered and concentrated to yield a brown oil (7.69 g, 100%).

Ethyl 6-oxo-3-azabicyclo[3.2.1]octane-3-carboxylate ethylene ketal

3-Azabicyclo[3.2.1]octan-6-one ethylene ketal (7.69 g, 45.5 mmol) wasdissolved in methylene chloride (200 ml) and chilled to 0° C. To thissolution was added triethylamine (6.34 ml, 91.0 mmol), then ethylchloroformate (4.02 ml, 50.1 mmol) drop-wise. The reaction was warmed toambient temperature and stirred for 18 h. Saturated sodium bicarbonatesolution (100 ml) was added, and the organic layer was separated. Theaqueous layer was saturated with sodium chloride and extracted withmethylene chloride (1×100 ml). The organics were then combined, driedover sodium sulfate, filtered and concentrated. The crude brown residuewas then distilled on a Kugelrohr apparatus (0.2 mm Hg, unknowntemperature) to yield a clear, dark brown oil (6.72 g, 61.3%).

Ethyl 6-oxo-3-azabicyclo[3.2.1]octane-3-carboxylate

A 2% solution of aqueous sulfuric acid (100 ml) was added to ethyl6-oxo-3-azabicyclo[3.2.1]octane-3-carboxylate ethylene ketal (6.72 g,27.9 mmol) and the mixture was allowed to stir for 1 h. The mixture wasthen extracted with ethyl acetate (2×100 ml). The combined organiclayers were dried over potassium carbonate, filtered, concentrated byrotary evaporation, and then distilled on a Kugelrohr apparatus (0.2 mmHg, 132-162° C.) to yield a clear colorless oil (3.49 g, 64%).

Ethyl 6-hydroxy-6-(3-pyridinyl)-3-azabicyclo[3.2.1]octane-3-carboxylate

To a solution of 3-bromopyridine (1.04 g, 6.58 mmol) in dry diethylether (20 ml) at −78° C. was added 2.5 M n-butyllithium (2.63 ml, 6.6mmol). The reaction was stirred for 30 min under nitrogen. Thepyridinyllithium solution was then slowly transferred by cannula into asolution of ethyl 6-oxo-3-azabicyclo[3.2.1]octane-3-carboxylate (1.00 g,5.07 mmol) in THF (10 ml) at −78° C. The reaction was stirred 4 h at−78° C. and then quenched with saturated aqueous ammonium chloride (10ml). The reaction was then extracted with chloroform (3×25 ml), thecombined extracts dried over sodium sulfate, filtered, and concentratedby rotary evaporation. Excess pyridine was removed by repeatedazeotropic rotary evaporation with toluene to yield the desired product(1.20 g, 86%).

6-(3-pyridinyl)-3-azabicyclo[3.2.1]oct-6-ene

To ethyl6-hydroxy-6-(3-pyridinyl)-3-azabicyclo[3.2.1]octane-3-carboxylate (1.10g, 4.0 mmol) was added thionyl chloride (5 ml) and the mixture washeated to reflux for 1 h under nitrogen. Thionyl chloride was removed byazeotropic rotary evaporation with toluene to give a dark brown oil,which was suspended in a 20% solution of potassium hydroxide in ethanol(10 ml) and refluxed for 18 h. The reaction mixture was cooled to roomtemperature and concentrated by rotary evaporation. Then saturatedsodium chloride solution (10 ml) was added. The mixture was filtered.The collected solids were washed with chloroform (25 ml), and thefiltrate was extracted with chloroform (3×25 ml). The combinedchloroform extracts were dried over sodium sulfate, filtered,concentrated by rotary evaporation, and distilled on a Kugelrohrapparatus to yield a light brown oil (350 mg, 47%).

6-(3-pyridinyl)-3-azabicyclo[3.2.1]oct-6-ene dihydrochloride

6-(3-Pyridinyl)-3-azabicyclo[3.2.1]oct-6-ene (190 mg, 1.0 mmol) wasdissolved in ethanol (5 ml), and 12 N HCl (2 ml) was added. The solutionwas sonicated for 3 min, and then concentrated by azeotropic rotaryevaporation with ethanol (3×5 ml) to yield a fluffy solid. Then the saltwas dissolved in hot isopropanol (2 ml), and diethyl ether was addeduntil a milky solution formed. Cooling in the freezer produced a lightbrown solid. The solid was filtered, washed with diethyl ether, anddried under high vacuum to yield6-(3-pyridinyl)-3-azabicyclo[3.2.1]oct-6-ene dihydrochloride, (230 mg,87%, m.p. 192-195° C.).

Example 10

Example No. 10 is 3-methyl-6-(3-pyridinyl)-3-azabicyclo[3.2.1]oct-6-enedihydrochloride, which was prepared in accordance with the followingtechniques:

3-Methyl-6-(3-pyridinyl)-3-azabicyclo[3.2.1]oct-6-ene dihydrochloride

Formic acid (98%, 5 ml) and formaldehyde (37% aqueous, 1 ml) were addedto 6-(3-pyridinyl)-3-azabicyclo[3.2.1]oct-6-ene (38 mg, 0.2 mmol) andthe solution was refluxed for 1 h under nitrogen. The reaction was thenconcentrated by rotary evaporation, and the residue was converted to afreebase with saturated bicarbonate solution (10 ml) and extracted withchloroform (4×5 ml). The combined extracts were dried over sodiumsulfate, filtered and concentrated by rotary evaporation. The residuewas purified by Kugelrohr distillation. The hydrochloride salt wasformed by addition of 12 N HCl to a solution of the compound in ethanol(10 ml), followed by azeotropic rotary evaporation with ethanol (3×5 ml)to yield a light white foam (44.4 mg, 79%).

Example 11

Example No. 11 is 7-(3-pyridinyl)-3-azabicyclo[3.3.1]non-6-enedihydrochloride, which was prepared in accordance with the followingtechniques:

Dimethyl 5-oxocyclohexane-1,3-dicarboxylate

To an suspension of 5-methoxyisophthalic acid (20.00 g, 102.0 mmol) indry methanol (75 ml) was added anhydrous ammonia (750 ml) (the ammoniagas was liquefied at −78° C. directly into the flask). Sodium metal (6.8g, 0.30 mol) was cut into small pieces and carefully added to the flaskover one hour. The solution changed from a pink to a yellow brown colorover the course of the sodium addition. After stirring for 1 h at −78°C., solid ammonium chloride (50 g) was added. The mixture was thenwarmed to ambient temperature over a period of 1 h. The pH of thereaction was then lowered to 2 with concentrated HCl. Saturated aqueousammonium chloride (100 ml) was added and the reaction mixture wasextracted with diethyl ether (6×50 ml). The combined ether extracts weredried over anhydrous sodium sulfate, filtered and concentrated by rotaryevaporation. The residue was dissolved in DMF (30 ml), treated withK₂CO₃(24.0 g, 174 mmol) and stirred for 1 h. Methyl iodide (26.69 g,173.9 mmol) was added in one portion and the reaction was stirredovernight at ambient temperature. Brine (30 ml) was then added, and thereaction was extracted with ethyl acetate (4×50 ml). The combinedorganic extracts were dried over sodium sulfate, filtered, andconcentrated by rotary evaporation. The viscous liquid residue wasdissolved in hexanes, from which the ketodiester separated as clearcolorless crystals (6.5 g, 32% yield).

Dimethyl 1,4-dioxaspiro[4.5]decane-7,9-dicarboxylate

To a solution of dimethyl 5-oxocyclohexane-1,3-dicarboxylate (6.0 g, 28mmol) in toluene (50 ml) was added ethylene glycol (3.73 g, 56.6 mmol)and p-toluenesulfonic acid (65 mg). The reaction was refluxed overnight,using a Dean-Stark trap to remove the excess water. The reaction wasworked up by removing the toluene by rotary evaporation, adding brine(10 ml) and extracting with ethyl acetate (3×40 ml). The combinedextracts were dried over sodium sulfate, filtered and concentrated byrotary evaporation to give the desired product as a thick colorlessliquid (6.0 g, 82%).

7,9-Bis(hydroxymethyl)-1,4-dioxaspiro[4.5]decane

To a solution of dimethyl 1,4-dioxaspiro[4.5]decane-7,9-dicarboxylate(6.0 g, 23 mmol) in dry THF at 0° C. was added lithium aluminum hydride(4.67 g, 68.7 mmol) under argon. The reaction was then refluxedovernight. The reaction was cooled to 0° C., and diethyl ether (100 ml)was added followed by drop-wise addition of 5 N NaOH until the graylithium aluminum hydride was converted to a white solid. The reactionmixture was then filtered through a Celite pad, which was then washedwith diethyl ether (100 ml). The combined filtrates were dried oversodium sulfate, filtered and concentrated by rotary evaporation to givethe alcohol as a viscous colorless liquid (6.3 g, 93%).

7,9-Bis(methylsulfonyloxymethyl)-1,4-dioxaspiro[4.5]decane

To a solution of 7,9-bis(hydroxymethyl)-1,4-dioxaspiro[4.5]decane (6.3g, 21 mmol) in dry dichloromethane (100 ml) with triethylamine (8.90 ml,63.8 mmol) was added methanesulfonyl chloride (4.11 ml, 53.2 mmol)drop-wise at 0° C. The reaction was allowed to come to ambienttemperature and stir overnight. The reaction was quenched with saturatedsodium bicarbonate (50 ml) and allowed to stir for 15 min. Afterseparation, the aqueous layer was extracted with dichloromethane (1×50ml). The combined extracts were dried over potassium carbonate, filteredand concentrated to give a dark brown liquid (7.3 g, 97%).

Ethyl 3-aza-7-oxobicyclo[3.3.1]nonane-3-carboxylate ethylene ketal

To a suspension of7,9-bis(methylsulfonyloxymethyl)-1,4-dioxaspiro[4.5]decane (7.3 g, 20mmol) in 30% NH₄OH (50 ml) was added copper(I) iodide (20 mg). Thereaction was then heated at reflux for 18 h. After the reaction mixturewas concentrated by rotary evaporation, saturated sodium bicarbonatesolution (20 ml) was added, followed by ethyl chloroformate (3.88 ml,40.6 mmol). This mixture was then stirred overnight at ambienttemperature under nitrogen. Then it was extracted with ethyl acetate(4×40 ml). These extracts were combined, dried over potassium carbonate,filtered and concentrated by rotary evaporation to give the a lightbrown liquid (4.5 g, 90%).

Ethyl 7-oxo-3-azabicyclo[3.3.1]nonane-3-carboxylate

Ethyl 7-oxo-3-azabicyclo[3.3.1]nonane-3-carboxylate ethylene ketal (4.40g, 17.2 mmol) was combined with 2% aqueous H₂SO₄(50 ml) and stirred for4 h. Then the reaction mixture was extracted with ethyl acetate (4×30ml). The combined extracts were dried over sodium sulfate, filtered andconcentrated by rotary evaporation to yield a light yellow oil (3.20 g,88.1%).

Ethyl7-(trifluoromethylsulfonyloxy)-3-azabicyclo[3.3.1]non-6-ene-3-carboxylate

Lithium diisopropylamide (LDA) was formed at −78° C. by adding 2.5 Mn-butyllithium (3.3 ml, 8.2 mmol) to diisopropylamine (1.16 ml, 8.28mmol) in THF (100 ml), followed by stirring for 30 min under nitrogen.The LDA was then transferred by cannula into a stirring solution ofethyl 7-oxo-3-azabicyclo[3.3.1]nonane-3-carboxylate (1.16 g, 5.49 mmol)in THF (50 ml) at −78° C. The solution was allowed to warm to −40° C.over 45 min, at which point2-[N,N-bis(trifluoromethylsulfonyl)amino]-5-chloropyridine (4.32 g, 11.0mmol) was added in one portion. The reaction was allowed to stir andwarm to 0° C. over 2 h, at which point it was quenched with saturatedsodium bicarbonate solution (100 ml). The layers were separated and theaqueous layer was extracted with ether (2×25 ml). The combined organicswere then washed with 1 N HCl (100 ml), saturated solutions of sodiumbicarbonate and brine (1×50 ml each), dried over sodium sulfate,filtered and concentrated by rotary evaporation. The residue was thenpurified by column chromatography, using a hexane/ethyl acetate gradient(20-40% ethyl acetate) as eluent, to obtain a light yellow oil (1.31 g,69.7%).

Ethyl 7-(3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene-3-carboxylate

To a solution of ethyl7-(trifluoromethylsulfonyloxy)-3-azabicyclo[3.3.1]non-6-ene-3-carboxylate(0.34 g, 1.0 mmol) in dimethoxyethane (8 ml) was added saturated sodiumcarbonate solution (2.5 ml), lithium chloride (127 mg, 3.0 mmol) andpyridinylboronic acid (123 mg, 1.00 mmol). The flask was alternatelyevacuated and filled with argon three times. Then palladiumtetrakistriphenylphosphine (23 mg, 0.02 mmol) was added and theevacuate/fill procedure performed once again. The flask was then sealedunder argon and the stirred reaction mixture was heated at 95° C. for 2h. The mixture was cooled to room temperature and then diluted withether (10 ml) and filtered through a Celite pad. The Celite was washedwith 30% ammonium hydroxide (25 ml) and ether (50 ml). The combinedfiltrates were separated into organic and aqueous phases, and theaqueous layer was extracted with ether (1×25 ml). Chloroform (20 ml) wasadded to the combined organic layers, and the mixture was dried oversodium sulfate and filtered. Concentrated of the filtrate by rotaryevaporation, followed by purification of the residue (207 mg) by columnchromatography, using a gradient of chloroform/methanol (0 to 2%methanol) as eluent, gave a light yellow oil (90 mg, 33%).

7-(3-Pyridinyl)-3-azabicyclo[3.3.1]non-6-ene dihydrochloride

7-(3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene-3-carboxylic acid ethylester (90 mg, 0.03 mmol) was dissolved in concentrated 12 N HCl (10 ml)and refluxed overnight. The reaction was then concentrated by rotaryevaporation, and the residue was converted to a free base with saturatedsodium bicarbonate (˜20 ml). The mixture was treated with saturated withsodium chloride (˜3 g) and extracted with chloroform (3×10 ml). Thecombined organic extracts were dried over sodium sulfate, filtered andconcentrated by rotary evaporation. The residue was purified by columnchromatography, using methanol/chloroform (10% methanol with 1% ammoniumhydroxide) as eluent, to yield 26.2 mg of the free base. ConcentratedHCl (5 drops) was added to a solution of the free base in ethanol (10ml). The excess HCl and residual water were removed by repeatedazeotropic rotary evaporation with ethanol. The crude salt was dissolvedin hot isopropanol (5 ml) and diluted with diethyl ether (1 ml). Thesolution turned cloudy and was allowed to slowly cool for 1 h. Whitecrystals formed on the sides. The supernatant was decanted, and thesolid was washed with a 20% ether/isopropanol solution and dried on ahi-vacuum pump. This gave 7-(3-pyridinyl)-3-azabicyclo[3.3.1]non-6-enedihydrochloride as a white powder (14 mg, 16%, m.p. 219-221° C.).

Example 12

Example No. 12 is 7-(3-pyridinyl)-3-azabicyclo[3.3.1]nonanedihydrochloride, which was prepared in accordance with the followingtechniques:

7-(3-pyridinyl)-3-azabicyclo[3.3.1]nonane dihydrochloride

7-(3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene dihydrochloride (17.2 mg,0.0629 mmol) was dissolved in methanol (10 ml), and 10% Pd/C (5 mg) wasadded. The mixture was hydrogenated for 3 h using a hydrogen-filledballoon. When the reaction was complete, the reaction was filteredthrough Celite, washed with methanol and concentrated by rotaryevaporation to a light brown solid. This was dissolved in ethanol (10ml) and treated with concentrated HCl (5 drops). The excess HCl andresidual water were removed by repeated azeotropic rotary evaporationwith ethanol. 7-(3-Pyridinyl)-3-azabicyclo[3.3.1]nonane dihydrochloridewas isolated as a white solid (18.2 mg, 100%). GC-MS shows a 85:15 ratioof diastereomers.

Example 13

Example No. 13 is 3-methyl-7-(3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,which was prepared in accordance with the following techniques:

3-Methyl-7-(3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene dihydrochloride

7-(3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene dihydrochloride (90 mg,0.33 mmol) was dissolved in 37% aqueous formaldehyde (3 ml), and 98%formic acid (10 ml) was added. This mixture was refluxed for 1 h. Thereaction was then cooled, concentrated by rotary evaporation, andtreated with saturated sodium bicarbonate solution (15 ml). It was thenextracted with chloroform (3×15 ml), and the extracts were dried oversodium sulfate, filtered and concentrated by rotary evaporation.Concentrated HCl (5 drops) was added to a solution of the free base inethanol (10 ml). The excess HCl and residual water were removed byrepeated azeotropic rotary evaporation with ethanol.3-Methyl-7-(3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene dihydrochloridewas isolated as a white, hygroscopic solid (116 mg, >100% due tomoisture content).

Example 14

Example No. 14 is 6-methyl-4-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-enedihydrochloride, which was prepared in accordance with the followingtechniques:

6-Methyl-4-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene dihydrochloride

To a suspension of 4-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-enedihydrochloride (90 mg, 0.35 mmol) in 15 mL of dichloromethane was addeda solution of formaldehyde (37% aqueous, 0.15 mL, ˜1.8 mmol). Withvigorous stirring, solid sodium triacetoxyborohydride (300 mg, 1.4 mmol)was added in two portions. The reaction was allowed to stir overnight atambient temperature. The reaction mixture was quenched by the additionof a sodium hydroxide solution (10% aqueous, approximately 1 mL), andthe whole extracted with dichloromethane (2×10 mL). The organic extractswere washed successively with water and brine (10 mL each), and driedover sodium sulfate. Filtration and removal of solvent in vacuo gave aresidue, which was dissolved in a small volume of methanol and treatedwith approximately 1 mL of 4M HCl in dioxane. The resulting solution wasconcentrated in vacuo, and the residue taken up in a minimum amount ofwarm isopropanol. After cooling briefly, ether was added to the point ofcloudiness, and the solution cooled slowly to ambient temperature. Asticky solid precipitate formed which resisted crystallization. Solventswere removed in vacuo, leaving the product as a hygroscopic, gummy mass(30 mg, 32%).

Example 15

Example No. 15 is4-(5-methoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene, which wasprepared in accordance with the following techniques:

4-(5-Methoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene

To a solution of t-butyl4-trifluoromethanesulfonyloxy-6-azabicyclo[3.2.1]oct-3-ene-6-carboxylate(200 mg, 0.560 mmol) in dimethoxyethane (4 mL) was added a saturatedsolution of sodium carbonate (1 mL), lithium chloride (72 mg, 1.7 mmol)and 5-methoxy-3-pyridinylboronic acid (128 mg, 0.837 mmol). The reactionmixture was evacuated under high vacuum and filled with nitrogen threetimes, then tetrakis(triphenylphosphine)palladium(0) catalyst (40 mg)was added. The reaction mixture was stirred vigorously and heated underreflux for 45 min. The dark mixture was diluted with ethyl acetate (20mL) and filtered though a Celite pad into 14% aqueous ammonium hydroxide(10 mL). The mixture was extracted with ethyl acetate (2×15 mL), thecombined organics washed with brine (2×15 mL), and dried over anhydrousmagnesium sulfate. Concentration by rotary evaporation gave a dark oil,which was purified by column chromatography, using a hexane/ethylacetate gradient (0-100% ethyl acetate) as eluent, to afford the productas a colorless oil (120 mg, 68%). A solution of the oil indichloromethane (5 mL) was treated with trifluoroacetic acid (1 mL) atambient temperature for 2 h. Removal of solvent by rotary evaporationleft a residue, which was treated with a few drops of concentratedammonium hydroxide. The water was removed by azeotropic evaporation withof ethanol (3×5 mL). The residue was taken up in dichloromethane andfiltered though a cotton plug to give, after concentration, a yellow oil(30 mg, 100%).

Example 16

Example No. 16 is6-methyl-4-(5-methoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene, whichwas prepared in accordance with the following techniques:

6-Methyl-4-(5-methoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene

A mixture of 4-(5-methoxy-3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene (15mg, 0.07 mmol), aqueous formaldehyde (37%, 0.25 mL) and 90% formic acid(1 mL) was heated at reflux for 1½ h. The mixture was concentrated underreduced pressure, and the remaining volatiles were removed by azeotropicevaporation with methanol (three times). The residue was made basic withdilute aqueous sodium hydroxide and extracted into dichloromethane. Theextracts were dried over anhydrous sodium sulfate, filtered andconcentrated. The crude product was chromatographed on a silica gelcolumn, eluting with 90:10:1 dichloromethane/methanol/concentratedammonium hydroxide. Concentration of selected fractions gave the productas an oil (9.0 mg, 56%).

Example 17

Example No. 17 is4-(3-methyl-5-isoxazolyl)-6-azabicyclo[3.2.1]oct-3-ene, which wasprepared in accordance with the following techniques:

tert-Butyl 4-ethynyl-6-azabicyclo[3.2.1]oct-3-ene-6-carboxylate

To a solution of t-butyl4-trifluoromethanesulfonyloxy-6-azabicyclo[3.2.1]oct-3-ene-6-carboxylate(1.8 g, 5.0 mmol) in 10 mL of toluene was added 20 mL of triethylamine,followed by trimethylsilylacetylene (0.49 g, 5.0 mmol). The mixture wasdegassed, placed under a nitrogen atmosphere, and copper iodide (50 mg)and bis(triphenylphosphine)palladium dichloride (100 mg) were added. Thereaction mixture was heated under reflux for 16 h, then cooled andconcentrated under reduced pressure. The residue was chromatographed ona silica gel column, using 0-50% ethyl acetate in hexane as eluent, togive tert-butyl4-trimethylsilylethynyl-6-azabicyclo[3.2.1]oct-3-ene-6-carboxylate (900mg, 58.9%). This was dissolved in 25 mL of methanol and treated withsolid potassium carbonate (˜1 g) with vigorous stirring. After 4 h, themixture was concentrated to dryness in vacuo, and the residue was columnchromatographed on silica gel, eluting with 2:1 hexane/ethyl acetate, togive a yellow oil (300 mg, 25.8% for two steps).

tert-Butyl4-(3-methyl-5-isoxazolyl)-6-azabicyclo[3.2.1]oct-3-ene-6-carboxylate

To a solution of acetaldoxime (65 mg, 1.1 mmol) in 15 mL of chloroformwere added 2 drops of pyridine, followed by N-chlorosuccinimide (146 mg,1.1 mmol). After stirring the cloudy mixture for 1 h at ambienttemperature, tert-butyl4-ethynyl-6-azabicyclo[3.2.1]oct-3-ene-6-carboxylate (233 mg, 1.00 mmol)was added in 2 mL of chloroform, followed by drop-wise addition oftriethylamine (0.175 mL, 1.25 mmol). The mixture was stirred at ambienttemperature for 4 h and then concentrated to dryness under reducedpressure. The residue was chromatographed on a silica gel column, with agradient of 2:1 hexane/ethyl acetate to 2:1 ethyl acetate/hexane, togive first recovered starting material, then tert-butyl4-(3-methyl-5-isoxazolyl)-6-azabicyclo[3.2.1]oct-3-ene-6-carboxylate(100 mg, 40%).

4-(3-Methyl-5-isoxazolyl)-6-azabicyclo[3.2.1]oct-3-ene

A solution of tert-butyl4-(3-methyl-5-isoxazolyl)-6-azabicyclo[3.2.1]oct-3-ene-6-carboxylate (80mg, 0.28 mmol) in 10 mL of dichloromethane was treated withtrifluoroacetic acid (2 mL) with ice bath cooling. After stirring 2 hand warming to ambient temperature, the reaction mixture wasconcentrated to dryness under reduced pressure. The residue was madebasic with 10% potassium hydroxide solution and extracted withchloroform (2×10 mL). The extracts were dried over anhydrous sodiumsulfate, filtered and concentrated to give the desired product as aviscous oil (30 mg, 58%).

Example 18

Example No. 18 is 6-(3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene, whichwas prepared in accordance with the following techniques:

Cyclohex-3-enylmethylamine

To a stirred suspension of lithium aluminum hydride (3.70 g, 100 mmol)in 200 mL of THF, cooled in an ice bath, was added drop-wise a solutionof cyclohexene-3-carbonitrile (10.7 g, 100 mmol) in 50 mL of THF. Afteraddition was complete, the mixture was heated at reflux for 14 h. Themixture was cooled in an ice bath, diluted with 200 mL of ether, andquenched by careful sequential addition of 3.7 mL of water, 5.5 mL of10% NaOH, and 4 mL of water. After stirring for 1 h, the mixture wasfiltered and concentrated to give the product amine, as a colorlessliquid (10 g, 90%).

Ethyl cyclohex-3-en-1-ylmethylcarbamate

Cyclohex-3-enylmethylamine (10 g, 90 mmol) was dissolved in 200 mL ofdichloromethane and cooled in an ice bath. Triethylamine (16.8 mL, 120mmol) was added, followed by drop-wise addition of ethyl chloroformate(10.9 g, 0.100 mol). The mixture was stirred overnight at ambienttemperature, then washed with water, dilute HCl, dilute aqueous sodiumhydroxide, and brine (50 mL each). The organic layer was dried overanhydrous magnesium sulfate, filtered and concentrated under reducedpressure to give the crude carbamate (14 g, 85%).

Ethyl N-(hydroxymethyl)cyclohex-3-en-1-ylmethylcarbamate

A sample of ethyl cyclohex-3-en-1-ylmethylcarbamate (5.1 g, 28 mmol) in500 mL of THF was treated with paraformaldehyde (16.7 g, 560 mmol),potassium carbonate (7.8 g, 56 mmol) and cesium carbonate (1.8 g, 5.6mmol). The mixture was stirred vigorously and heated under reflux for 4h. The mixture was cooled, filtered and concentrated under reducedpressure. The residue was column chromatographed on silica gel, using3:1 hexane/ethyl acetate as eluent, to give a colorless oil (3.6 g,61%).

Ethyl 3-azabicyclo[3.3.1]non-6-ene-3-carboxylate

To a stirred solution of ethylN-(hydroxymethyl)cyclohex-3-en-1-ylmethylcarbamate (213 mg, 1.00 mmol)in 15 mL of dichloromethane, cooled in an ice bath, was added drop-wiseboron trifluoride etherate (0.19 mL, 1.5 mmol). The initially cloudyreaction mixture slowly cleared. After it had become homogenous, it waswarmed to ambient temperature and stirred for 1.5 h. The reaction wasquenched by sequential addition of 5 mL of water and 5 mL of 10% KOHsolution. The mixture was extracted with dichloromethane (2×20 mL), andthe combined extracts were washed with brine (25 mL), dried overanhydrous sodium sulfate and concentrated under reduced pressure. Theresidue was column chromatographed on silica gel with 2:1 hexane/ethylacetate to give the product as a colorless oil (145 mg, 74%).

Ethyl 6-hydroxy-3-azabicyclo[3.3.1]nonane-3-carboxylate

A solution of ethyl 3-azabicyclo[3.3.1]non-6-ene-3-carboxylate (2.50 g,12.8 mmol) in 75 mL of THF was cooled in an ice bath and borane-THF (1Min THF, 19 mL, 19 mmol) was added drop-wise. The reaction was stirred atabout 10° C. for 3.5 h, then cooled in ice bath. A solution of sodiumhydroxide (2.4 g, 60 mmol) in 10 mL water was added drop-wise, followedimmediately by an additional 50 mL of THF and 10 mL of water. Hydrogenperoxide (30% aqueous, 8.5 g, 75 mmol) was then added, and the mixturestirred overnight at ambient temperature. The mixture was extracted withether (2×50 mL), and the combined extracts were washed with water andbrine (25 mL each). Drying over anhydrous magnesium sulfate, followed byfiltration and concentration under reduced pressure, gave the product asa colorless, viscous oil (2.2 g, 80%).

Ethyl 6-oxo-3-azabicyclo[3.3.1]nonane-3-carboxylate

A solution of oxalyl chloride (1.31 mL, 15 mmol) in 50 mL ofdichloromethane was cooled in a dry ice-acetone bath, and DMSO (1.4 mL,20 mmol) was added drop-wise over 5 min. After 10 min, ethyl6-hydroxy-3-azabicyclo[3.3.1]nonane-3-carboxylate (2.2 g, 10 mmol) in 10mL dichloromethane was added over 5 min. The mixture was stirred for 20min, and then triethylamine (6.3 mL, 45 mmol) was added slowly. Themixture was stirred for 1.5 h, gradually warming to −10° C. The reactionwas quenched by addition of water (25 mL). The organic layer wasseparated, washed with brine (25 mL), dried over anhydrous sodiumsulfate, filtered and concentrated under reduced pressure to give ayellow oil. This was chromatographed on a silica gel column, with 2%methanol in dichloromethane, to give the desired ketone (1.0 g, 45%).The chromatography also provided a sample of the isomeric ketone, ethyl7-oxo-3-azabicyclo[3.3.1]nonane-3-carboxylate, and some un-reactedalcohol starting material.

Ethyl6-trifluoromethanesulfonyloxy-3-azabicyclo[3.3.1]non-6-ene-3-carboxylate

A solution of LDA was generated by adding n-butyllithium (2.4 mL of 2.5M, 6.0 mmol) to a solution of diisopropylamine (0.84 mL, 6.0 mmol) in 30mL of THF at 0° C. A solution of ethyl6-oxo-3-azabicyclo[3.3.1]nonane-3-carboxylate (633 mg, 3.00 mmol) in 5mL of THF was then added drop-wise, at −78° C., to the LDA. Afterstirring 45 min and warming to −30° C., the solution was re-cooled to−78° C. and treated with2-(N,N-bis(trifluoromethanesulfonyl)amino-5-chloropyridine (1.77 g, 4.50mmol). The dark brown reaction mixture was stirred for 3 h, warmingslowly to ambient temperature, and was quenched by the addition of asaturated aqueous sodium bicarbonate. The mixture was extracted withether (2×50 mL), and the ether extracts were washed with a dilute sodiumcarbonate solution, water and brine (50 mL each). The ether solution wasthen dried over anhydrous magnesium sulfate, filtered and concentratedunder reduced pressure. The resulting crude product was columnchromatographed on silica gel, with a 0-5% gradient of methanol indichloromethane, to give the desired enol triflate (0.32 g, 31%).

Ethyl 6-(3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene-3-carboxylate

A mixture of ethyl6-trifluoromethanesulfonyloxy-3-azabicyclo[3.3.1]non-6-ene-3-carboxylate(270 mg, 0.790 mmol) in 6 mL of dimethoxyethane, 1.5 mL of saturatedsodium carbonate solution, 3-pyridineboronic acid (146 mg, 1.20 mmol)and lithium chloride (99 mg, 2.37 mmol) was degassed and placed under anargon atmosphere (5 min purge). Tetrakis(triphenyphosphine)palladium(0)(60 mg) was added, and the reaction mixture was heated at reflux for 4h. It was then cooled and filtered though a plug of silica gel, elutingwith ethyl acetate. Concentration of the filtrate and columnchromatography of the residue, with a gradient of 0-5% methanol indichloromethane, gave a yellow oil (130 mg, 60%).

6-(3-Pyridinyl)-3-azabicyclo[3.3.1]non-6-ene

A mixture of ethyl6-(3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene-3-carboxylate (100 mg,0.370 mmol) and 1.5 mL of concentrated HCl was heated under reflux for16 h. The mixture was cooled in an ice bath and made basic by adding 5 Maqueous sodium hydroxide. The suspension was extracted with chloroform(3×5 mL), and the extracts were dried over anhydrous sodium sulfate,filtered and concentrated under reduced pressure. The residue wasfiltered though a plug of silica gel, eluting with 90:10:1dichloromethane/methanol/concentrated ammonium hydroxide, to give theproduct as an oil (11 mg, 15%).

Example 19

Example 19 is 7-(5-isopropoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-enehemigalactarate, which was prepared in accordance with the followingtechniques:

7-(5-Isopropoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-enehemigalactarate

To a solution of ethyl7-(trifluoromethylsulfonyloxy)-3-azabicyclo[3.3.1]non-6-ene-3-carboxylate(0.12 g, 0.35 mmol) in dimethoxyethane (3 mL) was added saturated sodiumcarbonate solution (1 mL), lithium chloride (0.04 g, 0.9 mmol) and5-isopropoxy-3-pyridinylboronic acid (0.12 g, 0.66 mmol). The flask wasalternately evacuated and filled with argon three times.Tetrakis(triphenylphosphine)palladium(0) (0.01 g, 0.01 mmol) was added,and the evacuation and argon fill was performed once again. The flaskwas sealed under argon, and the stirred reaction mixture was heated at95° C. for 2 h. The mixture was cooled to ambient temperature, dilutedwith water (10 mL), and extracted with chloroform (3×5 mL). Thechloroform extracts were dried over anhydrous sodium sulfate andfiltered. Concentration of the filtrate by rotary evaporation, followedby purification of the residue by silica gel column chromatography,using a gradient of 0-2% methanol in chloroform as eluent, gave 0.16 gof a light yellow oil. This was dissolved in ethanol (20 mL) and addedto a stirred 50% aqueous KOH solution (10 mL). The mixture was thenrefluxed for 6 days. The ethanol was evaporated, and brine (20 mL) wasadded to the residue. Three chloroform extracts (15 mL each) were thentaken, dried (Na₂SO₄) and concentrated. The residue was columnchromatographed on silica gel, using a gradient of 0-1% concentratedammonium hydroxide in 85:15 chloroform/methanol, to yield the free base(36.1 mg, 0.14 mmol). This was then dissolved in 5 mL of isopropanol, towhich galactaric acid (20 mg, 0.095 mmol) was then added. The cloudysuspension was both heated and stirred while water was added drop-wiseto the suspension. When the solution turned clear, it was filtered hotand then slowly cooled to ambient temperature and stored overnight. Whenno crystallization occurred, the solution was concentrated 2.5 mL andkept at 0° C. for 3 hours. The white precipitate was collected bysuction filtration and washed with cold isopropanol. After high vacuumdrying (ambient temperature, 6 h) 4.8 mg (9.4%) of7-(5-isopropoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-enehemigalactarate (m.p. 172° C.) remained.

Example 20

Example 20 is 7-(5-phenyl-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-enehemigalactarate, which was prepared in accordance with the followingtechniques:

Ethyl7-(5-phenyl-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene-3-carboxylate

To a solution of ethyl7-(trifluoromethylsulfonyloxy)-3-azabicyclo[3.3.1]non-6-ene-3-carboxylate(0.12 g, 0.35 mmol) in dimethoxyethane (3 mL) was added saturated sodiumcarbonate solution (1 mL), lithium chloride (0.04 g, 0.9 mmol) and5-phenyl-3-pyridinylboronic acid (0.12 g, 0.7 mmol). The flask wasalternately evacuated and filled with argon three times. Thentetrakis(triphenylphosphine)palladium(0) (0.01 g, 0.01 mmol) was added,and the evacuation and argon fill was performed once again. The flaskwas then sealed under argon, and the stirred reaction mixture was heatedat 95° C. for 2 h. The mixture was cooled to ambient temperature,diluted with water (10 mL) and extracted with chloroform (3×5 mL). Thecombined extracts were dried over sodium sulfate and filtered.Concentration of the filtrate by rotary evaporation, followed bypurification of the residue by silica gel column chromatography, using agradient of chloroform/methanol (0-2% methanol) as eluent, gave ethyl7-(5-phenyl-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene-3-carboxylate as alight yellow oil (0.12 g, 90%).

7-(5-Phenyl-3-pyridinyl)-3-aza-bicyclo[3.3.1]non-6-ene hemigalactarate

A solution of ethyl7-(5-phenyl-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene-3-carboxylate(0.10 g, 0.29 mmol) in ethanol (20 mL) was added to a stirred 50%aqueous KOH solution (10 mL). The mixture was then refluxed for 3 days.The ethanol was evaporated, and brine (20 mL) was added to the residue.Three chloroform extracts (15 mL each) were then taken, dried (Na₂SO₄)and concentrated. The residue was column chromatographed on silica gel,using a gradient of 0-2% concentrated ammonium hydroxide in 85:15chloroform/methanol, to yield the free base (30.1 mg, 0.109 mmol). Thiswas dissolved in 5 mL of isopropanol, to which galactaric acid (13 mg,0.062 mmol) was added. The cloudy suspension was both heated and stirredwhile water was added drop-wise to the suspension. When the solutionturned clear, it was filtered hot and slowly cooled to ambienttemperature, at which temperature it was kept overnight. The precipitatewas filtered off and washed with cold isopropanol. After high vacuumdrying (ambient temperature, 6 h), the white solid weighed 23.3 mg(56.1%, m.p. 186° C.).

Example 21

Example 21 is 7-(5-phenoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-enehemigalactarate, which was prepared in accordance with the followingtechniques:

Ethyl7-(5-phenoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene-3-carboxylate

To a solution of ethyl7-(trifluoromethylsulfonyloxy)-3-azabicyclo[3.3.1]non-6-ene-3-carboxylate(0.13 g, 0.38 mmol) in dimethoxyethane (3 mL) was added saturated sodiumcarbonate solution (1 mL), lithium chloride (0.04 g, 0.9 mmol) and5-phenoxy-3-pyridinylboronic acid (0.17 g, 0.79 mmol). The flask wasalternately evacuated and filled with argon three times. Then,tetrakis(triphenylphosphine)palladium(0) (0.01 g, 0.01 mmol) was added,and the evacuation and argon fill was performed once again. The flaskwas sealed under argon, and the stirred reaction mixture was heated at95° C. for 2 h. The mixture was cooled to ambient temperature, dilutedwith water (10 mL), extracted with chloroform (3×5 mL). The extractswere dried over sodium sulfate and filtered. Concentration of thefiltrate by rotary evaporation, followed by purification of the residueby silica gel column chromatography, using a gradient of 0-2% methanolin chloroform/as eluent, gave ethyl7-(5-phenoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene-3-carboxylate asa light yellow oil (0.12 g, 87%).

7-(5-Phenoxy-3-pyridinyl)-3-aza-bicyclo[3.3.1]non-6-ene hemigalactarate

A solution of ethyl7-(5-phenoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene-3-carboxylate(0.12 g, 0.33 mmol) in ethanol (20 mL) was added to a stirred 50%aqueous KOH solution (10 mL). The mixture was then refluxed for 3 days.The ethanol was evaporated, and brine (20 mL) was added to the residue.Three chloroform extracts (15 mL each) were then taken, dried (Na₂SO₄)and concentrated. The residue was column chromatographed on silica gel,using a gradient of 0-2% concentrated ammonium hydroxide in 85:15chloroform/methanol, to yield the free base (54.1 mg, 0.185 mmol). Thiswas dissolved in 5 mL of isopropanol, to which galactaric acid (20 mg,0.095 mmol) was added. The cloudy suspension was both heated and stirredwhile water was added drop-wise to the suspension. When the solutionturned clear, it was filtered hot and slowly cooled to ambienttemperature, where it was kept overnight. The precipitate was filteredoff and washed with cold isopropanol. After high vacuum drying (ambienttemperature, 6 h), the white solid weighed 40.7 mg (55.5%, m.p. 176°C.).

Example 22

Example 22 is 7-(5-methoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-enehemigalactarate, which was prepared in accordance with the followingtechniques:

7-(5-Methoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene hemigalactarate

To a solution of ethyl7-(trifluoromethylsulfonyloxy)-3-azabicyclo[3.3.1]non-6-ene-3-carboxylate(0.32 g, 0.93 mmol) in dimethoxyethane (8 mL) was added saturated sodiumcarbonate solution (2.5 mL), lithium chloride (0.12 g, 2.8 mmol) and5-methoxy-3-pyridinylboronic acid (0.29 g, 1.9 mmol). The flask wasalternately evacuated and filled with argon three times.Tetrakis(triphenylphosphine)palladium(0) (0.02 g, 0.02 mmol) was added,and the evacuation and argon fill was performed once again. The flaskwas sealed under argon, and the stirred reaction mixture was heated at95° C. for 2 h. The mixture was cooled to ambient temperature, dilutedwith water (10 mL) and extracted with chloroform (3×5 mL). Thechloroform extracts were dried over sodium sulfate and filtered.Concentration of the filtrate by rotary evaporation, followed bypurification of the residue by silica gel column chromatography, using agradient of 0-2% methanol in chloroform, gave 0.41 g of a light yellowoil. This was dissolved in ethanol (40 mL) and added to a stirred 50%aqueous KOH solution (20 mL). The mixture was then refluxed for 16 h.The ethanol was evaporated, and brine (20 mL) was added to the residue.Three chloroform extracts (20 mL each) were then taken, dried (Na2SO4)and concentrated. The residue was dissolved in toluene (20 mL),concentrated again and column chromatographed on silica gel, using agradient of 95:5:1 to 90:10:2 chloroform/methanol/concentrated ammoniumhydroxide as eluent, to yield the free base (100 mg, 33%). A portion ofthis free base (40 mg, 0.17 mmol) was dissolved in isopropanol (3 mL)and treated with galactaric acid (20 mg, 0.095 mmol). The mixture wasthen swirled and heated as water was slowly added. When the mixtureclarified, it was filtered hot and the filtrate cooled. After sitting atambient temperature overnight, the mixture was filtered, to yield awhite solid, which was washed with cold isopropanol and high vacuumdried (ambient temperature, 6 h) to yield 11.5 mg (7.9%, m.p. 162-164°C.).

Example 23

Example 23 is 6-(5-phenoxy-3-pyridinyl)-3-azabicyclo[3.2.1]oct-6-enetrifluoroacetate, which was prepared in accordance with the followingtechniques:

Ethyl6-hydroxy-6-(5-phenoxy-3-pyridinyl)-3-azabicyclo[3.2.1]octane-3-carboxylate

To a solution of 3-bromo-5-phenoxypyridine (0.51 g, 2.0 mmol) in drydiethyl ether (15 mL) at −78° C. was added 2.5 M n-butyllithium (0.80mL, 2.0 mmol). The reaction was stirred for 30 min under nitrogen at−78° C. and then slowly transferred by cannula into a solution of ethyl6-oxo-3-azabicyclo[3.2.1]octane-3-carboxylate (0.20 g, 1.0 mmol) in THF(15 mL) at −78° C. The reaction was stirred 4 h at −78° C. and thenwarmed to ambient temperature overnight, at which time it was quenchedwith saturated aqueous ammonium chloride (20 mL). The mixture was thenextracted with chloroform (2×10 mL), and the combined extracts weredried over sodium sulfate, filtered, and concentrated by rotaryevaporation. Excess pyridine was removed by repeated azeotropic rotaryevaporation with toluene, and the residue was chromatographed on asilica gel column (with 5% methanol in chloroform) to yield the desiredproduct (0.31 g, 84%).

6-(5-Phenoxy-3-pyridinyl)-3-azabicyclo[3.2.1]oct-6-ene trifluoroacetate

To ethyl6-hydroxy-6-(5-phenoxy-3-pyridinyl)-3-azabicyclo[3.2.1]octane-3-carboxylate(0.31 g, 0.84 mmol) at 0° C. was added triethylamine (0.47 mL, 3.4 mmol)and thionyl chloride (0.18 mL, 2.5 mmol). The mixture was heated atreflux for 18 h under nitrogen. The volatiles were removed by azeotropicrotary evaporation with toluene (2×10 mL) to give a dark brown oil,which was suspended in a 50% solution of potassium hydroxide (5 g) inethanol (10 mL) and refluxed for 18 h. The reaction mixture was cooledto ambient temperature and concentrated by rotary evaporation. Thenbrine (10 mL) was added, and the mixture was filtered. The collectedsolids were washed with chloroform (25 mL), and the filtrate wasextracted with chloroform (3×25 mL). The combined chloroform extractswere dried over sodium sulfate, filtered and concentrated by rotaryevaporation. Preparative HPLC purification of the residue, using 0.1%trifluoroacetic acid in an acetonitrile/water gradient, gave the desiredproduct as a trifluoroacetate salt (77 mg, 29%).

Example 24

Example 24 is 6-(5-phenyl-3-pyridinyl)-3-azabicyclo[3.2.1]oct-6-enetrifluoroacetate, which was prepared in accordance with the followingtechniques:

Ethyl6-hydroxy-6-(5-phenyl-3-pyridinyl)-3-azabicyclo[3.2.1]octane-3-carboxylate

To a solution of 3-bromo-5-phenylpyridine (0.23 g, 1.0 mmol) in THF (5mL) at ambient temperature was added 2.0 M isopropylmagnesium chloridein THF (0.5 mL). The reaction was stirred for an hour under nitrogen.Then a solution of ethyl 6-oxo-3-azabicyclo[3.2.1]octane-3-carboxylate(0.21 g, 1.0 mmol) in THF (2 mL) was added. The mixture was stirred atambient temperature overnight, concentrated and quenched with water (1mL). The mixture was extracted with chloroform (2×10 mL), and thecombined extracts were dried over magnesium sulfate, filtered, andconcentrated by rotary evaporation. The compound was purified by silicagel column chromatography (1:1 ethyl acetate/hexane) to yield 50 mg ofproduct (13%).

6-(5-Phenyl-3-pyridinyl)-3-azabicyclo[3.2.1]oct-6-ene trifluoroacetate

To ethyl6-hydroxy-6-(5-phenyl-3-pyridinyl)-3-azabicyclo[3.2.1]octane-3-carboxylate(0.13 g, 0.37 mmol) at 0° C. was added triethylamine (0.30 mL, 1.2 mmol)and thionyl chloride (0.06 mL, 0.8 mmol). The mixture was heated atreflux for 18 h under nitrogen. The volatiles were removed by azeotropicrotary evaporation with toluene (2×20 mL) to give a dark brown oil,which was suspended in a 50% solution of potassium hydroxide in ethanol(10 mL) and refluxed for 18 h. The reaction mixture was cooled toambient temperature and concentrated by rotary evaporation. Then brine(10 mL) was added, and the mixture was filtered. The collected solidswere washed with chloroform (25 mL), and the filtrate was extracted withchloroform (3×25 mL). The combined chloroform extracts were dried oversodium sulfate, filtered, concentrated by rotary evaporation.Preparative HPLC purification of the residue, using 0.1% trifluoroaceticacid in an acetonitrile/water gradient, gave the desired product as atrifluoroacetate salt (59 mg, 43%).

Example 25

Example 25 is 6-(5-isopropoxy-3-pyridinyl)-3-azabicyclo[3.2.1]oct-6-enetrifluoroacetate, which was prepared in accordance with the followingtechniques:

Ethyl6-hydroxy-6-(5-isopropoxy-3-pyridinyl)-3-azabicyclo[3.2.1]octane-3-carboxylate

To a solution of 3-bromo-5-isopropoxypyridine (0.66 g, 3.1 mmol) in drydiethyl ether (15 mL) at −78° C. was added 2.5 M n-butyllithium (1.2 mL,3.0 mmol). The reaction was stirred for 30 min under nitrogen at −78° C.and then slowly transferred by cannula into a solution of ethyl6-oxo-3-azabicyclo[3.2.1]octane-3-carboxylate (0.30 g, 1.5 mmol) in THF(15 mL) at −78° C. The reaction was stirred 4 h at −78° C. and thenwarmed to ambient temperature overnight, at which time it was quenchedwith saturated aqueous ammonium chloride (20 mL). The reaction was thenextracted with chloroform (2×10 mL), and the combined extracts weredried over sodium sulfate, filtered, and concentrated by rotaryevaporation. Excess pyridine was removed by repeated azeotropic rotaryevaporation with toluene, and the residue was chromatographed on asilica gel column (with 5% methanol in chloroform) to yield the desiredproduct (0.34 g, 61%).

6-(5-Isopropoxy-3-pyridinyl)-3-azabicyclo[3.2.1]oct-6-enetrifluoroacetate

To ethyl6-hydroxy-6-(5-isopropoxy-3-pyridinyl)-3-azabicyclo[3.2.1]octane-3-carboxylate(0.34 g, 1.0 mmol) at 0° C. was added triethylamine (0.57 mL, 4.1 mmol)and thionyl chloride (0.23 mL, 3.1 mmol). The mixture was heated toreflux for 18 h under nitrogen. The volatiles were removed by azeotropicrotary evaporation with toluene (2×10 mL) to give a dark brown oil,which was suspended in a 50% solution of potassium hydroxide in ethanol(10 mL) and refluxed for 18 h. The reaction mixture was cooled toambient temperature and concentrated by rotary evaporation. Then brine(10 mL) was added, and the mixture was filtered. The collected solidswere washed with chloroform (25 mL), and the filtrate was extracted withchloroform (3×25 mL). The combined chloroform extracts were dried oversodium sulfate, filtered, concentrated by rotary evaporation.Preparative HPLC purification of the residue, using 0.1% trifluoroaceticacid in an acetonitrile/water gradient, gave the desired product as atrifluoroacetate salt (60 mg, 47%) (mp 133-134° C.).

Example 26

Example 26 is the syntheses of the 5-substituted-3-pyridinylboronicacids that were not commercially available (i.e., 5-methoxy,5-isopropoxy, 5-phenoxy and 5-phenyl). These were produced from thecorresponding bromopyridines (the syntheses of which have been reportedin U.S. Pat. No. 5,861,423 and PCT WO 99/65876) by the procedure of Liet al., reported in J. Org. Chem. 67(15): 5394-5397 (2002). An example,the synthesis of the 5-methoxy-3-pyridinylboronic acid, is includedhere.

5-Methoxy-3-pyridinylboronic acid

Triisopropyl borate (29.3 mL, 128 mmol) was added over 2 min to asolution of 5-methoxy-3-bromopyridine (20.00 g, 106.4 mmol) in toluene(140 mL) and tetrahydrofuran (35 mL) at −40° C. To this solution wasadded 2.5 M n-BuLi (51.1 mL, 128 mmol) drop-wise over 35 min whilemaintaining the temperature at −40° C. After the addition was complete,the reaction was stirred an additional 30 min at −40° C. and then waswarmed to −15° C. over one hour. Into the reaction was poured 1 N HCl(175 mL), and the mixture was stirred vigorously for 30 minutes. Thelayers were separated, and the organic washed once with water (15 mL).The aqueous phases were combined and neutralized (to pH 7) with 5 NNaOH, at which point the boronic acid precipitated out. The biphasicmixture was extracted with THF (3×150 mL). The organic phases werecombined, dried over sodium sulfate, filtered, and concentrated to yield15.36 g of 5-methoxy-3-pyridinylboronic acid as a light brown solid(94%).

Example 27

Example 27 is a the pair of regioisomers,3-(5-pyrimidinyl)-6-azabicyclo[3.2.1]oct-2-ene trifluoroacetate and3-(5-pyrimidinyl)-6-azabicyclo[3.2.1]oct-3-ene trifluoroacetate, whichwas prepared in accordance with the following techniques:

3-(5-Pyrimidinyl)-6-azabicyclo[3.2.1]oct-2-ene trifluoroacetate and3-(5-pyrimidinyl)-6-azabicyclo[3.2.1]oct-3-ene trifluoroacetate

To a solution of a mixture of t-butyl3-trifluoromethanesulfonyloxy-6-azabicyclo[3.2.1]oct-2-ene-6-carboxylateand t-butyl3-trifluoromethanesulfonyloxy-6-azabicyclo[3.2.1]oct-3-ene-6-carboxylate(0.10 g, 0.30 mmol) in dimethoxyethane (2 mL) was added a saturatedsolution of sodium carbonate (0.80 mL), lithium chloride (26 mg, 0.62mmol) and pyrimidine-5-boronic acid (74 mg, 0.59 mmol). The flask wasalternately evacuated and filled with argon three times.Tetrakis(triphenylphosphine)palladium(0) (13 mg, 0.013 mmol) was added,and the evacuation and argon fill was performed once again. The reactionmixture was stirred vigorously and heated at reflux for 4 h. The darkmixture was partitioned between 5 M NaOH (1 mL) and chloroform (2 mL).The organic layer was collected and combined with a second chloroform (3mL) extract of the aqueous layer. This combined chloroform extracts weredried over sodium sulfate, filtered and concentrated. The residue wascombined with 10 mL of methanolic aqueous KOH (made by dissolving 35 gof KOH in a mixture of 25 mL of water and 100 mL of methanol) andrefluxed overnight. The reaction mixture was cooled, and the volatileswere evaporated. Preparative HPLC purification of the residue, using0.1% trifluoroacetic acid in an acetonitrile/water gradient, gave thedesired product as a trifluoroacetate salt (41 mg, 45%).

Example 28 Assessment of Analgesic Effects of Compounds of Example 1

The compounds of Example 1 (administered as the dihydrochloride salt ofa 3:1 mixture of 3-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-2-ene and3-(3-pyridinyl)-6-azabicyclo[3.2.1]oct-3-ene) were evaluated in thisExample using a “hot plate” test in mice. Briefly, the compounds ofExample 1 (0.03, 0.1 and 0.3 mg free base/kg) were subcutaneouslyadministered five minutes before the hot plate test. Morphine (10 mg/kg)was subcutaneously administered at 15 minutes before the test. Eachmouse was placed on a metallic hot plate maintained at 52±0.2° C. Thenociceptive reaction latency, characterized by licking reflex of theforepaws or by jumping off the hot plate, was recorded. The cutoff wasset to 30 seconds.

At 0.03, 0.1 and 0.3 mg/kg, the compounds of Example 1 increased thenociceptive threshold by +72, +68 and +152%, respectively. The rise inthe nociceptive reaction latency was significant for all doses. Theresults are tabulated below in Table 1.

TABLE 1 Dose Reaction Latency % Treatment (mg/kg) n (sec) variationSaline — 10 11.2 ± 0.7  — Morphine 10 10 29.4 ± 0.5* 163 Compounds 0.0310 19.3 ± 2.8* 72 of Example 1 0.1 10 18.8 ± 2.2* 68 0.3 10 28.2 ± 1.8*152 Results expressed as mean ± SEM Vehicle (saline) Dunnett's test: *indicates a significant difference in comparison with vehicle-treated“injured paw” group for P < 0.05The time course of the analgesic effect of the compounds of Example 1(0.1, 0.3 and 1.0 mg free base/kg) was also assessed using the hot platetest following oral administration. Each dose of the compounds wasadministered to separate groups of animals at either 5, 15, 30 or 60minutes prior to hot plate assessment. Morphine (60 mg/kg) and vehiclewere also orally administered to separate groups of animals either 5,15, 30, or 60 minutes before the test. Each mouse was placed on ametallic hot plate maintained at 52±0.2° C. The nociceptive reactionlatency, characterized by licking reflex of the forepaws or by jumpingoff the hot plate, was recorded. The cutoff was set to 30 seconds.

Morphine (60 mg/kg), at 15, 30 and 60 minutes after dosing,significantly increased nociceptive reaction latency in comparison withvehicle-control by +69%, +47% and +37%, respectively. The compounds ofExample 1 (1.0 mg/kg), at 5 and 15 minutes after dosing, significantlyincreased the nociceptive reaction latency by +82% and +97%,respectively compared to vehicle controls. Lower doses failed to modifythe nociceptive threshold when compared to the vehicle-treated group(data not shown).

A rat model of peripheral mononeuropathy (Bennett Model) was also usedto evaluate the antihyperalgesic properties of the compounds.

Briefly, peripheral mononeuropathy was induced by loose ligation of thesciatic nerve in anaesthetized rats (pentobarbital; 45 mg/kg byintraperitoneal route). Fourteen days later, the nociceptive thresholdwas evaluated using a mechanical nociceptive stimulation (paw pressuretest). An increasing pressure was applied onto the hindpaw of the animaluntil the nociceptive reaction (vocalization or paw withdrawal) wasreached. The pain threshold (grams of contact pressure) was measured inhindpaws, both ipsilateral (injured side) and contralateral (non-injuredside) to the site of sciatic ligation injury, at 10 minutes after theoral treatment for the compounds (1 mg/kg) and 60 minutes after dosingfor morphine (60 mg/kg) and vehicle.

The results were expressed as a) the nociceptive threshold (mean±SEM) ingrams of contact pressure for the injured paw and for the non-injuredpaw in the vehicle-treated group, and b) the percentage of variation ofthe nociceptive threshold calculated from the mean value of thevehicle-treated group.

In the vehicle-treated group, a statistically significant decrease inthe nociceptive threshold was evidenced in injured paw as compared tothe control paw, demonstrating a clear hyperalgesia in the rats. In thegroup treated with morphine (60 mg/kg), the nociceptive threshold wassignificantly increased in comparison to the vehicle-treated group (by+144%, 60 minutes after dosing). Ten minutes after being orallyadministered, 1 mg/kg of the compounds of Example 1 increased thenociceptive threshold in the injured paw to a lesser, but significant,extent (+20%, in comparison to the vehicle-treated group). No behavioralside-effects were observed following the dosing with the compounds. Theresults are tabulated below in Table 2.

TABLE 2 Control Paw Injured Paw Injured Paw Injured Paw Test ArticleVehicle Vehicle Compounds Morphine of Example 1 Dose (mg/kg) — — 1 60Nociceptive 310.0 ± 12.0 110.0 ± 9.5 132.0 ± 9.0* 268.0 ± 18.9 threshold(g) % Variation — — 20 144 Results expressed as mean ± SEM Vehicle(distilled water) Dunnett's test: * indicates a significant differencein comparison with vehicle-treated “injured paw” group for P < 0.05

For additional details and further guidance regarding the testprotocols, please see Bennett and Xie, Pain, 33:87-107 (1988); D'amourand Smith, J. Pharmacol. Exp. Ther., 72:74-79 (1941); and Grossman etal., J. Comp. Neurol., 206:9-16 (1982), all incorporated herein byreference.

Example 29 Summary of Biological Activity

The following compounds were evaluated using the techniques describedabove.

The biological data indicate that the compounds of the present inventionhave the ability to selectively bind with high affinity to the α7 (Kivalues from 300 pM to 10 μM) and α4β2 (Ki values from 100 pM to 24 nM)receptors, as indicated by relatively low binding constants, and in somecases bind at concentrations well below those concentrations requiredfor activation of muscle or ganglionic receptors. Thus, the dataindicated that the compounds have the capability of being useful intreating CNS disorders involving nicotinic cholinergic systems.

Furthermore, the data indicate that certain of these compounds do notcause any appreciable side effects at muscle sites or ganglionic sitesat concentrations effective for producing CNS effects orneurotransmitter release (as low as 30 nM for dopamine release), thusindicating a lack of undesirable side effects in subjects receivingadministration of those compounds at dose ranges at which CNS effectsand neurotransmitter release are elicited.

The foregoing is illustrative of the present invention and is not to beconstrued as limiting thereof. The invention is defined by the followingclaims, with equivalents of the claims to be included therein.

1. A method for the treatment of pain comprising administration of acompound of Formulae 1 or 2:

wherein k and p are each 1; m and n are individually 0 or 1; providedthat if m is 1, then n is 0, and if n is 1, then m is 0; Ar is pyridine,optionally substituted at any position with a substituent Z is selectedfrom the group consisting of lower alkyl, lower alkenyl, cycloalkyl,phenyl, benzyl, halo, —OR′, —NR′R″, —CF₃, —CN, —NO₂, —C≡CR′, —SR′, and—SO₂R′; where R′ and R″ are individually hydrogen, lower alkyl,cycloalkyl, phenyl, or benzyl, and R is hydrogen, unsubstituted loweralkyl, unsubstituted arylalkyl, unsubstituted alkoxycarbonyl, orunsubstituted aryloxycarbonyl; or a pharmaceutically acceptable saltthereof.
 2. The method of claim 1, wherein the compound is selectedfrom: 6-(3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,7-(3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,6-(3-pyridinyl)-3-azabicyclo[3.3.1]nonane,7-(3-pyridinyl)-3-azabicyclo[3.3.1]nonane,6-(5-methoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,7-(5-methoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,6-(5-methoxy-3-pyridinyl)-3-azabicyclo[3.3.1]nonane,7-(5-methoxy-3-pyridinyl)-3-azabicyclo[3.3.1]nonane,6-(6-methoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,7-(6-methoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,6-(6-methoxy-3-pyridinyl)-3-azabicyclo[3.3.1]nonane,7-(6-methoxy-3-pyridinyl)-3-azabicyclo[3.3.1]nonane,6-(5-isopropoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,7-(5-isopropoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,6-(5-isopropoxy-3-pyridinyl)-3-azabicyclo[3.3.1]nonane,7-(5-isopropoxy-3-pyridinyl)-3-azabicyclo[3.3.1]nonane,6-(5-phenoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,7-(5-phenoxy-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,6-(5-phenoxy-3-pyridinyl)-3-azabicyclo[3.3.1]nonane,7-(5-phenoxy-3-pyridinyl)-3-azabicyclo[3.3.1]nonane,6-(5-phenyl-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,7-(5-phenyl-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,6-(5-phenyl-3-pyridinyl)-3-azabicyclo[3.3.1]nonane,7-(5-phenyl-3-pyridinyl)-3-azabicyclo[3.3.1]nonane,6-(6-chloro-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,7-(6-chloro-3-pyridinyl)-3-azabicyclo[3.3.1]non-6-ene,6-(6-chloro-3-pyridinyl)-3-azabicyclo[3.3.1]nonane, and7-(6-chloro-3-pyridinyl)-3-azabicyclo[3.3.1]nonane, or apharmaceutically acceptable salt thereof.
 3. The method of claim 1,wherein the pain is neurologic, neuropathic, or chronic.
 4. The methodof claim 1, wherein the pain is inflammatory pain, pain associated witharthritis, pain associated with rheumatoid disease, pain associated withteno-synovitis, pain associated with vasculitis, neuropathic pain,trigeminal neuralgia, herpetic neuralgia, diabetic neuropathy pain,causalgia, low back pain, deafferentation syndromes, chronic pain,severe chronic pain, post-operative pain, or pain associated with one ormore of cancer, angina, renal or billiary colic, menstruation, migraine,and gout.
 5. The method of claim 1, wherein the pain is nociceptivepain.